Report on PADMA POLY COTTON KNIT FABRICS LIMITED

INTRODUCTION:

Textile and Garment industries play the most dominating and expanding role in Bangladesh economy. At the financial year 1993-94, textile was declared as a ‘Thrust Sector’ in Bangladesh. Govt. provided facilities, investors, arose and consequently Bangladesh textile and garment industries emerged as a prime currency earner. At the beginning, we used to export garments by making them from the imported fabrics and accessories we got only stitching charges of garments and resultantly the foreign currency retention was only 20 percent. Later on, we changed our strategy and implemented ‘Backward Linkage’ to make export-oriented garments from our made yarns and fabrics. That eventually fetched 78% of total export earning of the fiscal year 2005-6. In 2004-5 the sector earned US$6.4 billion, 13% up from 2003-4. In 2005-6, it has increased to US$8 billion. Currently Bangladesh has only 2.6% of global market share and is expected to increase its export volume to double in near future. As an LDC origin, our garments and textile products enjoy duty-free access to Canada, Australia, Japan and some European countries. To maintain the current world market position, plenty of textile and garments industries are being set up and this trend will hopefully be continued for the next 20 years. According to a recent newspaper report, one knit-dyeing factory is being established in every 6 days. A numbers of spinning mills are simultaneously growing to fulfill their huge demand of yarn. In 2004, the number of spindles for manufacturing yarn was 4.2 million and it should be increased 8 million above right now. Good news for the textile graduates as well as for our nation that Bangladesh is forwarding faster towards this direction.

Among this sector, Knit garments is growing very rapidly due to less investments, requirement grow of backwards linkage and high profit than woven garments. That’s why export of knit garments is increasing day by day.

As a final year student of department of Textile Technology, Textile education can’t be completed without industrial training. Because, this Training minimize the gap between the theoretical and practical knowledge. It also sets up our mind with industrial environment. We are very much gratitude to ‘ESQUIRE KNIT COMPOSITE LTD’ to give us such an opportunity to complete 8 weeks long industrial training. Which is a 100% export oriented knit dyeing and yarn dyeing industry. It has well planed and equipped fabric, dyeing, garments and printing unit. It’s dyeing section running by three software’s. The whole industry is planned by one software.

Moreover, the administration and management system is very good. It is fully approved by several multinational inspection firms.

 THE PROFILE OF THIS FACTORY

2. General information of this mill:

 4. COMPANY PROFILE

Whatever is your specification or quantity desired, our expertise and quality of service always remains the same. Modern production and techniques and flexible processes and procedures allow us to offer efficient service for small batch as well as large orders. Esquire Knit Composite is a 100% export- oriented company and work with the objective of achieving maximum customer satisfaction. The company has adopted innovative procedures and practices to meet customer expectations every time they deal with us. We always welcome any feedback or suggestions from clients in order to serve them better.

ORGANIZATIONAL STRUCTURE

5. Administration Section: 

5.1 Knitting Section:

5.2 Fabric and Yarn Dyeing Section:

5.3 Garments Section:

INTRODUCTION OF GREY FABRICS& THEIR ATTACH SPL

6. Grey Fabric:

In generally, which fabric is directly collected from the knitting section that contains some impurities and natural colour is called grey fabrics.

6.1 Grey fabrics are below:

1. Single jersey or Plain fabric:

–          One set needle is used to make this fabric.

–          Its face and back side is different.

–          After cutting curling is produced.

–          Sinker is used to construct this fabric.

–          Needles are placed on cylinder.

–          Drawing the loops away from the technical back and towards the technical face side of the fabric.

1. Lycra Single Jersey:

–          Its another name is plain fabric.

–          Fabrics contain an elastic type’s yarn that is called lycra yarn.

–          Knitting construction is same as like as single jersey.

1. Double jersey:

–          Two set needle are used to construct these fabrics.

–          Needles are placed on dial and cylinder.

–          No sinker is used.

–          After cutting no curling is produced.

–          Face and Back sides are same.

–          Rib and Interlock are Double jersey fabrics.

1. 1×1 Rib:

–          It’s a double jersey fabrics.

–          Used two sets of needle to make this fabrics.

–          Face and Back sides are same.

–          Needles are placed on dial and cylinder.

–          No curling after cutting.

–          Less compact.

–          No sinker is used.

1. 1×1 Lycra Rib:

–          Its contain an elastic types a yarn that is called lycra yarn.

–          Others are same.

     f. 2×2 Rib:

–          It’s a double jersey fabrics.

–          It’s designed is double face and double back.

–          Two sets needles are used.

–         Others are same as like as 1×1 Rib.

     g. 2×2 Lycra Rib:

–          Contains an elastic type’s yarn that is called lycra yarn.

–          Others are same as like as 2×2 Rib.

     h. Polo Pique:

–          Its another name is double cross-tuck.

–          Two course knit-tuck.

–          Two course tuck-knit.

1. Single Lacoste:

–          Its another name is Single cross-tuck.

–          Knit-tuck then all knit.

–          Tuck-knit then all knit.

1. Lycra Single Lacoste:

–          Contains an elastic type’s yarn that is called Lycra yarn.

–          Others construction are same.

1. Double Lacoste:

–          Its another name is back pique.

–          Two course knit-tuck then one coarses all knit.

–          Two courses tuck-knit the one coarses all knit.

1. Plain interlock:

–          It’s a double jersey fabric.

–          Two sets of needles are used to make this fabric.

–          Needles are placed on dial and cylinder.

–          Face and back sides are same.

–          More compact.

–          Surface is Smooth, feelings soft.

–          No tendency to curl after cutting.

1. CVC Fleece:

–          Its full name is chief value of cotton.

–          Here cotton percentage is more and polyester percentage is less.

–          It may be (40% + 60%, 35% + 65% etc.)

–          First, coarse all knit & third coarses all knit.

–          Second, coarse one tucks the all miss.

–           Fourth, coarses two miss, one tuck, one miss.

–          Before brushing these types of fabric is called terry fabric.

1. 100% Polyester fabric:

–          Its construct by only polyester yarn.

1. Grey mélange:

–          Combination of cotton and viscose yarn is called grey mélange.

–          Where percentage cotton is more and viscose percentage is less.

–          Its may be ( 99%  + 1%, 98%+2%,  95% +5%, 85%+15%, etc).

1.2 Various types of Fleece fabric:

1. 100% cotton fleece.
2. CVC fleece.
3. Polar fleece.
4. Micro fleece.
5. Value fleece.
6. Bounded fleece.
7. Terry fleece.

6.2 Process flow chart of polar fleece fabric:

BATCHING SECTION

7. Process Flow chart before Dyeing:

7.1 For undyed fabrics (Body part):

Batching

Turning

Sewing

7.2 For undyed Collar& Cuffs:

Batching

Adjusting with body part of fabric or collar and cuffs by hand.

Sewing.

7.3 For dyed Lycra fabric:

Batching.

Turning.

Convert the tube fabric into open form by slitting machine.

Heat setting.

Sewing to convert it into tube form.

7.4. Process flow chart for yarn dyed fabric before washing.

7.5. For Yarn dyed fabric (Body part):

Batching.

Turning.

Sewing.

7.6. For Yarn dyed fabrics (Collar& Cuffs):

Batching.

Adjusting the body part of fabrics or collar and cuffs by hand.

Sewing.

7.7. Batching:

                 Batching is the process by which the grey fabrics is prepared for turning or Sewing (only for collar and cuffs) and finally for pretreatment and dyeing (for grey fabrics) or washing (for yarn dyed fabrics) according to the machine capacity. It is the first step of dyeing. There are mainly three types are as follows below:

0. Weight measurement of the fabric (body part) and identification (if needed).
1. Weighing of Open width and Tube fabric & identification.
2. Collar and Cuff Counting (if needed), weighing, identification. (if needed).

Weight measurement and Identification (if needed) are main part of batching.

7.8. The necessity of weight measurement & counting of (collars & cuffs):

If we have to dye in a machine having than one nozzle then the weight and the length of the fabrics have to be same for producing the same shade of fabric in each nozzle. So, weigh measurement of fabrics & counting of collars & cuffs is very necessary.

7.9 The weight measurement m/c:

The numbers of weight measurement machines are two in this section. Capacity of one is 300kg and another is 150kg.

7.10. The necessity of identification of during batching:

If two fabrics have same type of yarn, construction, and nearly same diameter then it is difficult to identify them. So, some identification is done during batching.

7.11. The identification marks during batching:

–          The identification marks for the part is cutting the fabric in the top of tube fabric which is known as “chheda”.

–          The identification marks for the collars and cuff is done by adding fixed number of yarns some intervals.

7.12. Batching is performed by two forms of fabrics:

–          Open width forms.

–          Tube fabrics.

Open width fabrics:

–          When the fabric dia is more than 40’’ then it is called open fabric.

Tube fabrics:

               – When the fabric dia is less than 40’’ then it is called Tube fabrics.

N.B: But in 2×2 Rib fabrics, when the fabric dia is 35’’/38’’/39’’ then it will become open fabrics.

7.13 The function of batch man:

A batch man has some nozzle cards, some khata (each khata is for particular buyer), some batch khata & he has some responsibility as follows:

          – He must check the diameter of fabric (body part) or length & width of fabric (for collars & cuffs) if these are correct then, he can start the next step of the task.

          –  When he gets the Route card then, he opens the particular khata for particular order & he does some calculation for particular machine ( depending on the number of nozzle of machine) in one page of khata & he also writes the total weight of fabrics & identification marks in other page of khata after completing the weight measurement. Then, he writes the result in the batch khata.

          – He also writes the total weight of fabrics, fabrics type (e.g. organic cotton, cotton, Lycra etc) diameter, fabric, structure (single jersey, double jersey etc) number of rolls at the bottom side of the Route card with identification marks.

7.14 Batch planning:

Those main points which we should consider during batch planning are:

–          We have to try to use the machine having highest capacity according to weight of fabric. That is if the lot size be 1000kg then, we can use HT- 6 machine in Esquire knit composite which has the actual capacity is 1080kg.

–          The lot size & the machine capacity should be nearly close that is if the lot size would be 700kg then we will not use HT-6 machine in this factory having capacity 1080kg. We have to use HT-4/1 or HT-4/2 machine having capacity 720kg.

–          The weight & the length of fabric in each nozzle of one machine should have to be same or very close. Otherwise, the shade of dyed fabrics will be different in different nozzles.

–          If the two fabrics of same types having nearly diameter then, after dyeing or finishing it is difficult to identify them so some identification mark is necessary which is an important point of batching.

7.15. Example: 01

# Making a batch for HT-4/1 machine where fabric weight is 697.5kg.

Finish GSM: 310.                   Brand: NAHAR.                     Buyer: Mascot.

Yarn count: 20^s                     Yarn Lot: 0087.                        M/c: HT-4/1

                                              Colour: Black.

                                              Lot no: 86#

                                             Order no: 0058#

1. CVC Fleece 74” (open)   –     7 roll   – 149.60kg.

CVC 1×1 Rib 44” (open) –     1roll    – 25.5kg.

               B. CVC Fleece 74” (open)   –     8 roll   – 150.0kg.

                    CVC 1×1 Rib 44” (open) –    1 roll   – 24.5kg.

               C. CVC Fleece 74” (open)     –    8 roll – 150.0kg.

                   CVC 1×1 Rib 44” (open)   –     1 roll – 24.5kg.

               D. CVC Fleece 74” (open)     –    8 roll – 107.80kg.

                    CVC Fleece 69” (open)     –    2 roll – 42.3kg.

                    CVC 1×1 Rib 44” (0pen) –    1 roll – 10.8kg.

                    CVC 1×1 Rib 46” (open) –    1 roll – 7.5kg

                    CVC S/J        17” (tube) –      1 roll – 5.04kg

                                                    Total Roll= 40 roll – 697.5kg

Where, A, B, C, &D are indicated as M/C nozzle. Each nozzle contains180kg generally.

7.16. Batching faults:

–          Wrong weighing of body, collars & cuffs.

–          Wrong counting of collars & cuffs.

–          Wrong batch planning.

–          Wrong identification.

–          Incorrect ratio.

–          Batch master carelessness.

 PLANNING SECTION

8. The planning sequence for Esquire Knit composite Ltd is as follows:

                                               Order Sheet

                  (Monthly and weekly planning by merchandisers).

                                (Radio Frequency Diagram) RFD Plan

(made by planning department and delivered to all sectors that is dyeing, knitting, and Garments).

                                                Dyeing Plan

(Produced by the dyeing department which will be dyed in which machine and which day will be dyed is planned here. Batch planning is included here).

8.1. Some card from dyeing plans: 

                             According to dyeing plan this is area produced –

                                            Process Route Card

                                              (Supplied by IT)

                                                Nozzle Card

                                           (Supplied by Batch Man).

9. TURNER

9.1. Turner machine: 

The machine by which counting of rolls & face/back side of fabric is opened is called turner machine. One roll of fabric is adjusted with another roll of fabric by hand after turning. There are two types of turner machine.

1. manual turner machine  &
2. automatic turner machine

                                           Turner machine

Manual turner machine.                                              Automatic turner machine.

9.2. Manual turner machine:

 It is used when the fabric is required to day white (that is only optical brightener is used & no other colors) then the manual turner machine is used.

         – It can be also used if; light color is required to dye on the fabric.

         – the dirt/dust can adhere to the fabric if automatic turner machine be used which can be visible in light color or only optically brightened fabric. So the manual turner machine is used in this case.

9.3. Automatic turner machine: 

         – The automatic turner machine can work automatically. Most of the turning is completed here.

         – It can be used if; medium to deep shade is required to dye on the fabric.

         – The dirt/dust can adhere to the fabric if, automatic turner machine be   used but in medium to deep shade it will not be visible so this turner is used for this.

9.4. Special features of automatic turner machine:

–          Two pipes for blowing air

–          An engine inside of the machine

–          Two rollers (for delivering the fabric) on the upper side of the machine

–          3 buttons two for start two pipes individually the other is for stop the machine.

9.5. Construction of Turning m/c:

–          Padder.

–          Motor.

–          Air compressor.

9.6. The necessity of turning:

           – To remove some dirt from the fabric.

             – To count the number of rolls.

             – To make back side of appear on face side as required.

             – To make some identification on fabric.

             – To adjust all the rolls together with hand.

e.g. Some fabrics can be cut at the bottom side in fabric times and some are not (the fabric which are cut during turning is also cut after weight  measurement at the top side of the fabric and also a card is supplied by the people who takes the weight of the fabric. This identification system is known as “chheda” to the workers.

To make the back face side as required for a fabric.

To adjust all the rolls together with hand by knot for a nozzle.

They fulfill the turning row in process Route card and also fulfill the particular turning khata. Then, it goes for sewing.

9.7. Which fabrics are turning by m/c?

–          Single Lacoste.

–          Double Lacoste.

–          1×1 Rib.

–          2×2 Ribs.

9.8. Which fabrics are not turning by m/c?

–          Lycra single jersey (Turn over by hand).

–          CVC Fleece (Turn over by hand).

–          1×1 Lycra Rib.

–          Collar and Cuffs.

“CVC fleece” fabric is turned over by hand because, due to pressure of machine padder, it may be stained on fabric, which can create more problems during dyeing and brushing.

N.B: Lycra single jersey Turning two times.

9.9. Cause of Turning:

–          To turn over the fabrics face side to back side. Because, during dyeing when fabric face sides come to contact with m/c roller then fabrics – Strength, durability will be reduced.

–          Fabrics quality also may be damaged by continuous friction.

That’s why, by turning machine fabrics face side turn over to back so that during dyeing fabric quality is not damaged.

9.10. Heat setting Fabrics are:

–          Lycra single Jersey.

–          Lycra single Lacoste.

–          1×1 Lycra Rib.

–          2×2 Lycra Rib.

Heat setting is done by stentering machine at 190^oC temperature. As a result the Lycra fibres are stable in the fabric.

9.11. Lycra:

Lycra means elastic or rubbery types fibre/ yarn. Lycra’s extensibility is      (400-500).

9.12 For Stable of Lycra: (Stentering m/c)

Temperature: 190^oC to all Chambers.

M/c diameter: 10% (+).

Over feed     :  Control very carefully.

Allowance for full feeder Lycra: 10%

Half feeder Lycra                       : 5%.

9.12. Cause of heat setting:

 Lycra fabrics are heat setting because, during dyeing it can be created many problems such as:

–          Uneven dye.

–          Shade variation.

–          Colour is not penetrated into the fabric of fibre pores.

Actually, Lycra’s are stable in the fabrics by heart setting so that it can’t any hazardous acts during dyeing.

After heat setting the Lycra fabrics feelings become soft and smooth.

N.B: During batching the batch man is kept 11% allowance for cotton fabrics and for CVC, TC/PC fabrics is kept 7% allowance.

10. SEWING

10.1. Sewing:

            “Sewing means stitching”.

Here, objectives of sewing to add the small amount of fabric to big amount of fabric by roll wise and machine nozzle wise by stitching.

During sewing of all fabrics are stitching by white colour thread. Colour thread is not used because, during dyeing by colour bleeding from the thread, it may be stained on fabric surface along to sewing line.

# Generally, after dyeing there is not required sewing of the fabric. But sometimes if the fabric is off shade then redyeing is performed to get the required shade. Then only the off shade dyed fabrics are sewing.

# In heat setting the Lycra single jersey fabrics are sewing by two thread m/c. Because these fabrics are thin and light.

# Other all fabrics are sewing by three thread m/c. Because this type of fabrics are heavy thick. So sewing also be strong. Besides, Body part and collar-cuffs sewing also be strong.

10.2. Number of sewing machine: 3

The necessity of sewing:

                                           To adjust the rolls by sewing which is adjusted with hand by knotting in turning before sewing.

    They fulfill the sewing row in process Route Card and fulfill the particular sewing khata then it goes for dyeing.

 FABRIC DYEING SECTION

11.1. Lay –Out of Fabric dyeing:

FABRIC DYEING M/C.

11.2. There are dyeing machines in this section. These are described below:

 N.B: Here, Generally each nozzle contains 180kgs fabric.

11.3. Fabric Dyeing Machine (Sample)

1.7. Shown the machine arrangement fabric dyeing machine in this factory.

N.B: The total numbers of dyeing machines are 19. But, here shown only a few sample of dyeing.

11.4. There are 19 dyeing machines in knit dyeing section. These machines are of three companies as follows:

1. Sclavos
2. Fongs National Eng. (Shenzhen) Co. ltd.
3. Tong Geng Enterprise Co; Ltd

Sclavos has two brands:

1. Venus.
2. Ahtena.

Sclavos

7.8. The specification of Sclavos (Venus & Athena) is given here:

1. Machine type: Winch
2. Machine brand : Venus  &  Ahtena
3. Total number of knit dying machines in this factory : 14

            Machine name in this factory:

1. 4.      Number of tanks :4
   1. Tank 1
   2. Tank 2
   3. Salt tank
   4. Main tank

1. Tank 1:  Using for caustic soda, soda ash, & dyes are used to deliver to the main tank. The parts of tank 1 in described bellow:
2. Tank 2: The rewarded rest of chemicals & without salt everything is input into tank 2.
3. Salt tank: Only salt is used to put here. But for light shade the salt required is less. In that case salt is put into tank 1.
4. Main tank:  Here all the chemicals, dyes & salt are delivered from tank 1, tank 2 & salt tank. The pretreatment & dyeing is completed here.

1. Unloading reel: The fabric is used to unload from the machine by this part. The number of unloading reel is equal to the number of nozzle in the machine. It is rubber coated which helps to unload fabric easily.
2. Monitor:  It is situated at the right side of the machine. The commands are shown in the monitor & the operators can work from these commands. There are also some buttons for working properly & to obey these commands.
3. Alarm box: There is an alarm box on the upper side of the machine. There are also some buttons to operate the machine & to stop the alarm.
4. Plain board: It is situated at the right side of the machine.
5. Water level: There is a water level to know the amount of water in the main tank. It does not give correct result but it can give an approximate result. In Athena machine there in no water level but in Venus there is a water level.

11.5 The advantages of Athena over Venus are as follows:

1. Up to 50% of the machine capacity Athena machine can maintain equal liquor ratio but Venus machine can not maintain it.
2. In Athena machine both tanks have metallic mixture and air flow mixture parts. But in case of Venus machine tank-1 has a metallic mixture and tank 2 has an air flow mixture.
3. The capacity of Athena machine is higher than the Venus machine for the same number of nozzles.
4. Up to 50% of the machine capacity Athena machine can maintain equal liquor ratio but Venus machine can not maintain it.
5. In Athena machine both tanks have metallic mixture and air flow mixture parts. But in case of Venus machine tank1 has a metallic mixture and tank 2 has an air flow mixture.
6. The capacity of Athena machine is higher than the Venus machine for the same number of nozzles.

Fong’s

 11.6. The specifications of Fong’s dyeing machines are as follows:

1. Machine type: Winch
2. Machine brand: Fong’s
3. Total number of knit dying machine in this factory : 4
4. Machine name in this factory :

                                                 1. F-20/1

                                                 2. F-120/1

                                                 3. F-30/2

                                                 4. F-30/1

5. Capacity for highest temperate: 130 ^◦

6. Mixing tank: There is a tank in this machine. Every chemical are used to put here. There are some components here are as follows:

        a. Metallic mixing part: It is used to mix any solution

        b. Air flow mixing part: It is also to mix any solution.

        c. Steamer: It is used to delivery steam in mixing tank.

        d. Steam controller: It can control the amount of steam

        e. Filter: It is used to filter the solution which is transferred in to the main tank.

7.  Main tank: The chemical from the tank is transferred here. The pretreatment and dyeing are completed here.

8.  Monitor:  It is situated at the right side of the machine. The commands are shown in the monitor & the operators can work from these commands. There are also some options for working properly & to obey these commands.

9. Unloading reel: There is an unloading reel for unloading the dyed fabric.

10. Three detectors: There are 3 detectors on the above of the nozzle are as follows:

1. Temperature detector: It is at the left side between these 3 detectors which can detect the temperature of the main tank.
2. Fabric turning pressure detector: It is at the middle of these 3 detectors. It can detect the pressure at which the fabric turning.
3. Atmospheric pressure detector: It can detect the atmospheric pressure of the main tank.
4. Panel board: There is a panel board at the right side of the machine by which the programme can be set up.

TONG GENG

11.7. There are 3 types of Tong Geng dyeing machines in knit dyeing section:

1. HAF -1&2
2. NPL
3. Z

The specifications of HAF machine as follows:

1. Machine type : Winch
2. Machine brand : Tong Geng
3. Total number knit dyeing machine : 2
4. Machine names in this factory : HAF 30/1 and

  5.   Mixing tank: There is a tank in this machine. Every chemicals are used to put here.

There are some components here are as follows:

        a. Metallic mixing part: It is used to mix any solution

        b. Air flow mixing part: It is also to mix any solution.

        c. Steamer: It is used to delivery steam in mixing tank.

        d. Steam controller: It can control the amount of steam

        e. Filter: It is used to filter the solution which is transfer

7.  Main tank: The chemical from the tank is transferred here. The pretreatment and dyeing are completed here.

8.  Monitor:  It is situated at the right side of the machine. The commands are shown in the monitor & the operators can work from these commands. There are also some buttons for working properly & to obey these commands.

9. Unloading reel: There is an unloading reel for unloading the dyed fabric.

10. Three detectors: There are 3 detectors on the above of the nozzle are as follows:

1. Temperature detector: It is at the left side between these 3 detectors which can detect the temperature of the main tank.
2. Fabric turning pressure detector: It is at the middle of these 3 detectors. It can detect the pressure at which the fabric turning.
3. Atmospheric pressure detector: It can detect the atmospheric pressure of the main tank.
4. Panel board: There is a panel board by which the programmed can be set up.

N.B: In the above the NPL & Z type of machines are not present in this factory.

REEL SPEED OF A MACHINE

11.8.   Reel speed of a dyeing machine varies for different causes are as follows:

1. Reel speed depends upon the fabric structure. It is kept highest for the single jersey (plain) fabrics. Lowest for single lacoste and double lacoste fabrics. Medium for the 1×1 rib, interlock and other fabrics.
2. It also depends upon the type of fabrics. For collars and cuffs reel speed is kept lower but for body part it is kept higher for the same fabric structure. For collars and cuffs at higher reel speed tungle is a great problem. So the reel speed is kept lower.
3. It also depends upon the length of the fabric in a nozzle. If the fabric length is high in a nozzle then, the reel speed will be also high. If the GSM of a fabric is higher or the diameter of a fabric is higher or the diameter of a fabric is higher, the ultimately the fabric length will be lower and the reel speed will be also lower and vice- versa.

GSM of fabric          Fabric length       Reel speed        & vice- versa

Diameter of fabric          Fabric length         Reel speed       & vice- versa

1. It also depends upon the machine type. If the capacity of a nozzle is higher then the reel speed will be also higher & vice-versa.

 Complete dyeing

12.  Process definition:

12.1Dyeing:

            Colorizations of the Whole fabric or the entire bulk of the fabric is called dyeing.

      N.B: Colour produce due to the presence of chromophore group.

12.2. Printing:

           The Localized dyeing of the fabric according to the design is called Printing.

12.3. Dyes:

–          Either soluble or

–          Made soluble or

–          Dispersible.

–          Have to use in the aqueous medium.

–          Have the affinity to the fibre.

12.4. Pretreatment:

          The process by which the fabric is ready for dyeing and printing is called pretreatment.

12.5. Pretreatment Process:

–          Desizing.

–          Scouring.

–          Bleaching.

12.6. Desizing:

Removal of the size materials from the grey fabric is called desizing. Sizing materials- such as; Starch. e.t.c

                                                 Hydrolyse

      Desizing: insoluble starch                   insoluble dextrin                soluble dextrin

                                                                            Glucose                              Maltose

12.7 Desizing types:

           a. Hydrolytic desizing.

–          Rot steeping.

–          Acid steeping.

–          Enzymatic desizing.

       b. Oxidative desizing.

–          Chlorine desizing.

–          Chlorite desizing.

–          Bromite desizing.

N.B: Enzymes are protein in nature. But, after giving the high temperature enzyme can be broken.

12.8. Composition of cotton:

       Composition of cotton materials are as follows:

Disadvantages of reactive dyes: The main disadvantages of the reactive dyes are: Hydrolyses of the dye. Wastage of salt. Hydrolyses of dyes: At the same time when the dyes react with cellulose under alkaline condition, a certain amount of dyes also react with water, thereby removing the particular reactive group from the dyes. When this happens, the dye is said to be hydrolysed and is unable to react with the fibre anymore. Reaction: Dye – Cl-  +  H+ – OH-                   Dye – OH + HCl Problem Create during dyeing by hydrolyzing: Slower reaction . Reduces the efficiency of the fixation process. As it’s  a colored dyes, during subsequent washing may be possibility to colour bleed from the fabric. Some reactive dyestuff: For cotton: Amcazol.(1:20) Imcozine.(1:10) Bezaktive S- max & S-LF. Remazol RR.(1:10) Solacion. .(1:20) Drimarine – XN.(1:10) Cibacron. (1:10) Drimarine- CL.(1:10) Dychu – Fix.(1:10) Synozol.(1:10) Kimsoline.(1:10) Jakazole.(1:10) For Polyester: Taicron HWT Taicron XFT Dianix CC Dorospers Red XLD Lumacron Yellow S6GL 200% Lumacron Red SCBN Tex Cotech Sunfix Red S3B 50% Lumacron Turq. Blue SGL Dorospers  Crimson Dyeing Preparation Procedures: 01.  For light colour: Water temperature : 60oC Dyes weight           : 500 – 1000gm Water                     : 45 litres. Dye solution time  : 10 min. Filtering time         : 15 min. Mixing time           : 10 min Total time              : 30 – 35 min. Water temperature : 60oC. Dyes weight           : 1000 – 2000gm Water                     : 65 litres. Dyes solution time:   10 min. Filtering time        : 15 min. Mixing time          : 10 min. Total time              : 30 – 35 min. 02.  For medium colour: Water temperature : 60oC. Dyes weight          : 10 – 15 kg. Water                    :  70 litres. Dye solution time : 20 min. Filtering time        : 15 min. Mixing time          : 10 min. Total time             : 45 – 50 min. 03.  For dark colour: Water temperature : 60oC Dyes weight          : 30 – 40 kg. Water                    : 120 – 130 L Dye solution time : 30 min. Filtering time        : 15 min. Mixing time          : 15 min. Total time             : 60 min. Dyeing process/method for fabric dyeing: There are  7 types of dyeing methods apply in this factory. Isothermal process. Critical migration Process. Hot brand process(Turquoise colour). 100% Polyester dyeing process. CVC fabric dyeing process. White dyeing process. Bio-scouring method. Dyeing : There are mainly used 3 types of color dyeing processes. e.g. Isothermal  method Migration method Turquoise method Isothermal Process: In this  method dyes, salt, soda all are dozed at same temperature. (at 60 ◦ C). Fixation time depends on shade% : up to  2% = 30 min 2 – 5% = 40 min. Above 5% = 50 min. (Remazol, Amcazol, Imcozine, Bezaktive S-max, Drimarine –CL are include in this group). Process flow chart for (Dyeing SAS): Filling the machine with required water. Then dosing the required colour chemical as bellow: Then temperature raise at 60oC Run time 2 min at 60oC Then Check the PH of the solution ( PH Control 6 to 7 ). Then enter the dyes group for producing colour according to shade% Dozing time 15 min Run time 20 min at 60oC After that enter the required amount of Glauber’s salt at 60oC Dozing time 20 min Check the S.G of Salt (1-1.050) Run time 20 min at 60oC Then enter the required amount of Soda ash at 60oC Dozing time 30 min PH Check of Soda ash(10.5 -11.78). Then run time 40 min at 60oC Then cut the dyed sample for matching shade within 5/ 20 / 35 min.If ok the sample. Then drain out the water Soaping The soaping is the 3rd stage. It is done after dyeing. A typical process is described here: Draining water Filling with water 15 min Rinsing for a certain time at 60 ◦ C Then Acquachron 9 min at 60oC Acetic acid transfer into the dye bath at 60oC Run for 3 /4 /5 minutes PH is checked and acceptable vale is 6 to 7 Raising temperature up to 90 ◦ C & Detergent is added Sample check                        Treating for 10 minutes Rinsing is done by draining water. Fixing and softening: It is the 4th and last stage. It is done after soaping. A typical method of fixing and softening  is as follows: Draining the dye bath Filling with water Sample check, if ok then, Zetafix WER(Fixer) dozing to for 10 minutes Acetic acid and Crosoft  NBC(10% solution of 6 gm/l) Use softener dozing for 10 minutes PH is checked (4.8 – 5) Running time is (15 – 30) minutes. Draining the dye bath. Unload the dyed goods. Critical migration : In this method the leveling agent and dyes are dosed at normal temperature (40 –45)oC Then the temperature raised at 80oC and the salt is dosed at 80 ◦ C.    Then alkali is dosed at Cooling temperature at 60oC. Fixation time depends on the shade%:  Up to 4% = 60 min. Above4% = 90 min. (Bezaktive S-LF, Imcozine dyes group include this process). Dyeing stage: Colour chemical enters  at 40oC Run time at 4 min. Then dyes enter at 50oC Then temperature increases at 80oC Then Salt is dosed at 80oC Run time 20 min at 80oC. Then temperature fall at 60oC Then PH is checked if Ok then cut the sample for matching the approved shade. Then go to the next process ( Soaping, Softening & fixing.) Hot brand process ( Turquoise Process): In this process ,Dyes, salt , soda ash, and other chemicals are dozing at 60 ◦ C , then the temperature is raised at 80oC. At 80oC the process runs for 40 to 60 mins. Fixation time depends on the shade% : Up to 1% = 20 min. 1 – 2%    = 30 min. Above 2% = 40 min. Turq. Solazol(ex- Dark –Blue WR) include this process. Dyeing stage: Filling the machine with required water. Then dosing the required colour chemical as bellow: The above chemicals are dosing at 60oC Run time 3 min Then preparation of dyes are dosing at 60oC Run time 10  min at 60oC Then Check the PH of the solution ( PH Control 6 to 7 ). Then dosing the Glauber’s salt at 60oC Dozing time 21 min Run time 20 min at 60oC Check the S.G of Salt (1-1.050) Then enter the required amount of Soda ash at 60oC Dozing time 30 min PH Check of Soda ash(10.5 -11.78). After that run time 30 min Then raises the temperature at 80 to 85oC Then run time 40 min at 80 – 85oC Then cut the dyed sample for matching shade within 5/ 20 / 35 min.If ok the sample. Then drain out the water.(complete the dyeing stage) White Dyeing Process: Treating with Soda Ash, Contipon S(Anti foaming agent) for 15 minutes at  50 ◦ C added of  optical brightener at 50 ◦ C for 20 minutes followed by treating at 80 ◦ C  for 25 minutes. 100%Polyester Dyeing Process: Polyester dyeing is done at 130 ◦ C  without carrier . In this process there is no required any salt and soda . But requires it leveling chemicals to performs this process. It also requires acid, According to dyes group  to maintain PH. If Dianix – CC group of dyes then PH control 4.5 – 5 and if the –XFT groups of dyes the PH control 3 – 3.9. Fixation time depends on the shade% : Up to 1% = 20 min. 1-2%  = 30 min. Above 2% = 40 min. Step the 100% polyester dyeing process with disperse Dye-stuff: The sequence of dyeing process with Disperse dyes is as follows: Take water in the machine bath at required level. Then add Detergent, Sequestering agent, Anti-creasing agent, Dispersing agent. Circulate the fabric for 5 mins at 50oC. Add acetic acid and circulate for 5 mins at 50oC. Check PH of the dye bath. Add dye solution for linear dosing and circulate the for 10 mins at 50oC. Circulate the fabric and raise the temperature at 130oC. Continuing Circulate the fabric for 30 – 40 mins at a constant temperature at 130oC. Circulate the fabric and decrease the temperature at 60oC. Then Check the shade with approved shade. Rinse and Drain. For reduction Process: Add caustic soda and circulate for 3 mins at 50oC. Add Hydrose and raise the temperature at 80oC. Continue Circulating the fabric for 15 mins at constant temperature at 80oC. Then Drain. Add acetic acid and circulating for 10 mins at 60oC. At last final Drain. Unload. 12.  Process definition: 12.1Dyeing: Colorizations of the Whole fabric or the entire bulk of the fabric is called dyeing. N.B: Colour produce due to the presence of chromophore group. 12.2. Printing: The Localized dyeing of the fabric according to the design is called Printing. 12.3. Dyes: –          Either soluble or –          Made soluble or –          Dispersible. –          Have to use in the aqueous medium. –          Have the affinity to the fibre. 12.4. Pretreatment: The process by which the fabric is ready for dyeing and printing is called pretreatment. 12.5. Pretreatment Process: –          Desizing. –          Scouring. –          Bleaching. 12.6. Desizing: Removal of the size materials from the grey fabric is called desizing. Sizing materials- such as; Starch. e.t.c Hydrolyse Desizing: insoluble starch                   insoluble dextrin                soluble dextrin Glucose                              Maltose 12.7 Desizing types: a. Hydrolytic desizing. –          Rot steeping. –          Acid steeping. –          Enzymatic desizing. b. Oxidative desizing. –          Chlorine desizing. –          Chlorite desizing. –          Bromite desizing. N.B: Enzymes are protein in nature. But, after giving the high temperature enzyme can be broken. 12.8. Composition of cotton: Composition of cotton materials are as follows:

 12.9 Scouring:

            Grey fabrics contain fats, waxes, and other impurities. The absorbance of the fabric is adversely affected dye to the presence of these impurities. This leads to the improper dyeing, printing and finishing in the subsequent process. These impurities are removed from the fabric by a chemical treatment. This chemical treatment is called scouring process.

In generally, the process by which all the natural and added impurities except natural coloring matter are removed is called scouring. It is also known as kiering, kier-boiling.

12.10  Purpose of scouring process:

–          Used to make the fabric more absorbent.

–          Clean the fabric with the help of NaOH.

–          Remove all impurities both natural and added from the desized fabric.

12.11 Bleaching:

            Bleaching is a process which removes the natural nitrogenous matters, i.e. dirt, dust, husk, broken seed, protein, leaf etc. from the fabric and make it white by oxidizing or chemical treatment.

Purpose of Bleaching:

• To remove all the natural colouring materials.
• To impart adequate whiteness to the fabric.
• It changes the textile materials which are hydrophobic in nature.
• It increases the dye absorption ability of the textile materials.
• It helps to produce an even shade during dyeing operation.
• To impart the wet ability of the fabric which is necessary for further treatment and in domestic uses.  \

N.B: Actually, Bleaching process can not remove the full colour just break-down the colour producing part

12.12. Bleaching can be done by two ways:

• Oxidation process. (Preferable).
• Reduction process. (Is not preferable because, after some days it becomes yellowish colour on the fabric surface reoxidation process).

12.13. Bleaching agent:

• H₂O₂, i.e. Universal bleaching agent.  So it is used World-wide for its good performance.
• NaOCl, from here free chlorine comes-out. So, it is not used world-wide.
• Ca (OCl)_2.
• NaClO₂. etc.

12.14. Advantages of peroxide bleaching:

• Among the oxidizing agent, only H₂O₂ provides a high bleaching effect at a reasonable cost.
• No changes of reoxidation.
• Peroxide bleaching keeps the fibre quality.
• Cotton can be bleached with H₂O₂ in a single stage.
• In hot, alkaline peroxide has not only a bleaching effect but also a cleaning effect.

Reaction:

H₂O₂                            H⁺ +  HO₂^–

HO₂^–                     OH^– + [O]

[O]   +  [Colorant’s]                      Discolourisation.

H₂O₂ :

• Unstable in higher P^H & Alkaline medium.
• Unstable in higher temperature.
• Stable in lower P^H & Acidic medium.

N.B: To keep stable P^H  we used buffering agent. i.e. Silicates, Phosphates etc.

Specific gravity (S.G):

   The ratio of substances weight and at 4^oC temperature equal volume of weight of water is called specific gravity. Water S.G = 1000 kg/m³

                            Substances weight

S.G =                                                                                      ×ρ^θ

                    At 4^oC temperature equal volume of water

The S.G of salt is most important factor in dyeing because salts help to dye exhaustion or penetration in the fabric.

• If the S.G value of salt is less than standard value. Then dye penetration in to the fabric will not be good. For this reason we will have to notice so that salt & water is not more or less one each another. It will have to keep an equilibrium condition.
• If the S.G of salt is less than the target S.G. Then salt adds by calculating the salt percentage.
• If S.G of salt is increased then fabric will be dark shade. For reducing that a little amount of water is added to light it.

P^H :  The negative logarithm of  Hydrogen Ion is called P^H. P^H is an important factor for dyeing.

• If  P^H  = 0 – 6.9                  Acidic medium.
•      P^H  = 7                          Neutral medium.
•      P^H  = 7.1 – 14              Al kali medium.
• If the P^H is less in dyeing :

–          Shade of the fabric will be variation.

–          Dyes will be hydrolysed.

–          Uneven shade of the fabric.

• If P^H is more, then acid add to decrease or adjust P^H.
• If P^H is less, then Soda adds to increase or adjust P^H.

12.15. Time required for dyeing processing in different parameter:

• Without enzyme + Finishing- then processing time will be required at 8 hrs.
• With enzyme + Finishing – then processing time will be required at 10 – 11 hrs.

N.B: By SLF– groups of colour dyeing action always perform in MIGRATION process.

         Where, Colour chemicals add – (40 – 60)^oC

                                         Dyes add – (40 – 60)^oC

                                         Salts add  –  80 ^oC. Run time 30 min.

                                          Soda adds –  60 ^oC. Run time 30 min.

   By Bezaktive – SMX  groups of colour dyeing action always perform in ISOTHERMAL process.

• Remazol.
• Cibacron.
• Imcozine . where, Colour chemical adds – 60^oC

                                    Dyes adds                   – 60 ^oC

                                    Salt                             – 60 ^oC

                                    Soda                           – 60 ^oC

Here, exhaustion and fixation will be occurred at this same temperature.

12.16 Chemicals which are entered manually:

• Contipon S (10%).
• Reduzin ABC.
• Jinsofter BSK.
• Abutex – AP – 750. (42%)
• Caustic Soda (pearls).
• Glauber’s  salt.
• Soda Ash.
• Cotoblanc –NSR.
• MA- Prep –IN (Scour – AIN)
• Deco soft Jcc (10%).
• Lyogen PES.
•  Dyapol –AB.
• Dyapol –XLF.
• Antisil  Conz.
• Redupal – SU.
• Dyes.
• Jinsofter WCS (Flakes).
• Bluton sun white BVB/BMB.

12.17 Chemicals which are transferred automatically:

• Hydrogen per –oxide (H₂O₂ 35%).
• Reduzin –THN (50%).
• Acetic acid.
• Jinlev CL-225.
• Jintexalate –SQ-117.
• MA- Humi(terge –Ap) .Dark shade
• Hydrostat BM
• Liquid enzyme.
• Zetafix WER.
• Jintex Stab.

N.B: Fixing process is done during dark or deep shade.

N.B: SAS: If shade% is more then salt is added before dyes add. Some times salt is adding two  times in deep shade.

         DAS: If shade% is less then salt is added after dyes adding.

2. Process Requirement:

2.1 Software used:

      In this factory for total dyeing management used three software.

• SIDO MASTER.
• SDM – Used as a planning board.
• DOSA-TEX – Auto dozing Controller.

N.B: The whole industry uses a one software. Its name is “HAQUE –TEX’’ software.

2.2 Key Accessories:

      Key accessories used in this factory for pretreatment to complete dyeing are:

• Salt tank.
• Mixing tank.
• Machine tank.
• Bohme meter.
• P^H meter.
• Eye protecting glass.
• Hand gloves.
• Sewing machine.
• Gum boot.
• Hand lifter for carrying the batch.

2.3. Materials/ Chemical used:

     Following materials or chemicals are used in the pretreatment process:

• Water.
• Steam.
• Compressed air (for yarn dyeing).
• Antifoaming agent. (e.g. Contipon S).
• Detergent. (e.g. Reduzin ABC).
• Wetting agent. (Abutex – Ap-750(42% solution).
• Sequestering agent. (Reduzin ABC).
• Caustic Soda. (NaOH).
• Hydrogen peroxide. ( H₂O₂35%).
• Stabilizer. ( Jintex stab).
• Anti-creasing agent. ( Jinsofter –BSK)
• Hydrogen peroxide killer.( Reduzin –THN)
• Acetic acid.
• Enzymes for neps and dead cotton .(Hydrostat-BM).

3.0 Safety:

      In order to ensure  floor and personnel safety operations are instructed to follow the   safety guide lines given bellow:

• Smoking is strictly prohibited in the factory premises.
• Put on the safety masks while mixing or transferring alkali and acid.
• Operator must be cautious while handling hydrogen peroxide and caustic soda and use hand gloves, eye protecting glass for safety.
• During production, after reaching the optimum temperature(above 80^oC), in case the lid of the machine needs to be opened, operator must depressurize the machine and use hand gloves, eye protecting glass etc. while performing such task for safety.

4. Operation Procedure:

    Operation stuffs for pretreatment to complete dyeing includes below:

• Production manager.
• Assistant production manager.
• Sr. production Executive.
• Production Executive.
• Sr. supervisor
• Supervisor.
• Operator.
• Helper.

4.1 Checklist before operation.

• Checking the programme in Dosa-Tex software.
• Machine set-up.
• Fabric weight.
• Fabric quality.
• Yarn quality.
• Collar design (Tipping/ solid).
• Rib designs (Normal/Lycra).
• Chemical availability.
• Power availability.
• Steam availability.
• Water availability.
• Compressed air.
• Manpower availability.
• Fabric stitch is done properly.

4.2 Operation Procedure.

4.4.1 Scouring& Bleaching recipe:

         In this factory scouring and Bleaching are performed at the same time.

4.4.2. Scouring& Bleaching, Time and Temperature:

          The  Time and Temperature for the Scouring and Bleaching process are given below:

  There are two types of cotton dyeing in this factory these are as follows :

1. color dyeing
2. white dyeing ( OBA treated )

there are 3 steps in color dyeing are as follows:

1. pretreatment
2. dyeing &
3. soaping

  pretreatment:

                      the scouring and bleaching is done at a time this factory. The bio-polishing is not always done. If the yarn is not good, then, bio-polishing  is done .Other wise it is not done .

     The scouring and bleaching is described here step by step:

    # Pre-bleaching Process:

                                     Filling the machine with required water

                                      Fabric loading (normal temperature)

At 50^oC  the leveling chemicals are used are given below:

                                                     Enters at dye bath

                                                   Run time 4 minutes at 50^oC

 Temperature raising from 50 ^◦C to   60 ^◦C and during this time the Hydrogen peroxide 35%                                                        is transferring in to the dye bath .

At 60 ^◦ C run time for 2 minutes and the memory level(water level ) is corrected.

Temperature raised from 60 ^◦ C to 110 ^◦ C. During this time the Caustic soda pearls dosing is completed. Though, the

Required time for this increasing temperature is 20 minutes but  maximum in cases it takes 29 minutes to 31 minutes.

                                        Run time  20 minutes at  110 ^◦ C

Cooling from 110 ^◦ c to  95 ^◦ C  . Though the required time for this is 7 minutes but in maximum case it takes 10 to 12 minutes

Rinsing for 15 minutes which helps to decrease temperature from 95 ^◦ C  to 80 ^◦ C . Absorbency of the fabric is tested before the rinsing is stopped.

                                      Acquachron at 80^oC  for 15 min

Sample check(absorbency)

At 80 ^◦ C the Radujin THN (50% sol) is used as per-oxide killer is entered in to the dye bath.

                                   Run time for 10 minutes at 80 ^◦ C

                         The amount of per-oxide is checked if it is OK then

            Rinsing to decrease the temperature to 50 ^◦ C from  80 ^◦ C (acquachron for 17^/)

                                      The dye bath is again filled with water

                                   Then Acetic acid is added in to dye bath

                                    Run for 7 minutes with acetic acid at 50 ^◦ C.

                                                  Then rinsing at 50^oC

                                                        Then Drain.

                                       Pre-bleaching is completed here.

Antipilling/Enzyme treatment( if need):

The bio-polishing is done by Enzyme. This process is described here-

                Filling the machine with require water and enter the below chemical.

                                The above chemicals transferred in to bye bath

                                          Run time 50 minutes at 50 ^◦ C .

                                 pH is checked acceptable value is 4.5 to 5 if ok then,

                                                  the bath is drained

                                     Then water is again taken into bath and

                                    the chemicals Hydrostat –BM and Soda ash

                               Transferred in to the dye bath at normal temperature

                                       Then P^H is checked after 2/3 minutes

                                        Run time for 10 minutes at 80 ^◦ C

                                                     Water is drained 1 min.

                             the required amount of water is taken again in the dye bath

                                               Acetic acid is added at 45 ^◦ C

                                                   Run for 3 minutes

                                                            Rinsing

                                                      Then main drain

                                       Enzyme Treatment is completed here.

Dyeing Stage:

# Suitable dyestuff is used for dyeing to knit fabrics:

Reactive dyestuff:

The introduction of “Reactive dyes” by “ICI” in 1956 is an important landmark in the history of synthetic dyes. These dyes chemically reacts with the fibres (hence the name is reactive dyes) with the formation of covalent bond between the dye and the fibre.Dyeing of cotton fibres with these dyes under mild alkaline conditions resultants in a chlorine atom on the triazin ring which is replaced by an oxygen atom from the cellulose hydroxyl group.

Reaction:  

                   Cell-OH  +  OH                 Cell – O^–  + H₂O

                   Cell – O^– + Dye – Cl^–                   Cell – O – Dye  + Cl^–        

Properties of reactive dyes:

• Water soluble anionic dyes.
• During dyeing process reactive group makes Co-valent bond with fibre and stay in the  part of a fibre.
• Use in cellulosic and protein fibre.
• Any kind of shape produced by this dye.
• Washing fastness is very good.
• Rubbing fastness good.
• Good for making light shade.
• Low cost.
• Easy applicable.
• Fibre reacts with the dye to form covalent bond and become a part of the fibre.

Nature of reactive dyes: A covalent is thirty times stronger than Vander- walls force. Direct dye produce dull shade but reactive dyes produce bright shade.

Objectives of reactive dyes:

• To dyeing the cellulosic and protein fibre.
• To get all kind of shade by using this dyes.
• To increase the wet fastness.
• To increase the rubbing fastness.
• To reduce the cost.

Characteristics of structural features of reactive dyes:

                                                       S – C – B – X

  Where, S is the solubilizing group.

              C is the colored molecule.

              B is the bridging group.

              X is the reactive group.

Some reactive groups:

• DCT ( Dichloro triazine).
• MCT( Mono- chloro triazine).
• MFT( Mono- fluro triazine).
• NT   ( Nicotinyl triazine).
• TCP  ( Tri-chloro Pyrimidine).
• DCQ ( Di-chloro quinoxaline).
• DFCP ( Di-fluro chloro Pyrimidine)

The reactive groups undergo mainly two types of reaction:

• Neucleophilic substitution reaction.
• Neucleophilic addition reaction

Classification:

  Reactive dyes have been recently classified as;

• Alkali controllable.- which have relatively high reactivity and only moderate substantivity. They are applied at a low temperatures and level dyeing requires careful control of the addition of alkali to start to fixation. Example: DCT, DFCP,and VS.
• Salt- controllable dyes.- these dyes are of relatively low reactivity towards to cotton under alkaline conditions and then the dyeing temperature will be as high as 80⁰C . They have appreciable substantivity and level dyeing requires careful addition of salt to promote exhaustion. Example: TCP, MCT, as well as MFT. Reactive dyes.
• Temperature controllable dyes.- which undergo fixation at high temperatures even under neutral conditions. The NT dyes are in the class.

Basic principle of dyeing cotton with reactive dyes:

 Start dyeing with neutral solution, in presence of salt or gradually added to promote exhaustion.

No reaction of dye with fibre takes place . only absorption and migration of dye in the fibre.

                                                 Then appropriate alkali is added.

                   Acidic dissociation of cellulose takes place producing cellulosate ion.

                                               This starts the dye fibre reaction.

                                     Dyeing continued until no further dye is taken up.

                Through washing to remove the absorbed unfixed and hydrolyzed dyes.

Three steps of exhaust dyeing process:

• The initial exhaustion phase:  Dyeing is started in neutral solution so that there is little change of the to react with cellulose. During this stage some dyes will be absorbed by the fibres, the amount depends on its substantivity. The dye molecules migrate to promote level dyeing. Sodium chloride or sulphate will some times be present initially or be added gradually to promote exhaustion. The temperature of the bath may also be gradually increased to help penetration of dye into fibre and also assist migration.
• Fixation phase: After in exhaustion phase, the P^H of the dye bath is increased by complete or gradual addition of the appropriate type and amount of alkali. This causes dissociation of some of the hydroxyl groups in cellulose and cellulosate ions begin to react of the dye. The fixation process then results in additional dye absorption. Dye absorption from solution and reaction of the fibre then progress until no further dye is taken up.
• Washing phase: The dyed and rinsed fabric contains dye bonded to the cellulose, absorbed but unreacted dye, as well as hydrolyzed dye. There will also be residual alkali and salt which is relatively easy to remove by successive rinsing in cold and warm water. Maximum unfixed dyes should be washed out as much as possible. If this is not done, staining of materials in subsequent washing will result. Thorough washing using boiling detergent solution(soaping) eliminates the unfixed dyes. Soaping is repeated for deep dyeings or the remaining unfixed dye should be complexed with a cationic agent.

Cold brand reactive dyes:

          The  reactivity of the dyes is due to the chlorine atoms attached to the triazine ring. When two chlorine atoms are present in the dye molecule as in the case of Procion Yellow R, one of the chlorine atoms is so reactive that it reacts with the cellulose even at room temperature(20-30^oC) in the presence of alkali. Hence, such reactive dyes are called cold brand reactive dyes.

Hot brand reactive dyes:

         When only one chlorine atom is present in the dye molecule, the reactivity of the dye decreases considerably and the dyeing has to be carried out at a higher temperature(65- 80^oc).

Hence these dyes are called hot brand reactive dyes.

Vinyl Sulphone reactive dyes:

       Reactive dyes belonging to another reactive system( vinyl Sulphone system) have also become popular. Remazol dyes belong to this class. These are marketed in the form of Sulphatoethyle Sulphone dyes which when treated with mild alkali generates the vinyl group that in turns reacts with ionized cellulose to form the dye fibre bond.

• Excellent brightness.
• Wet fastness good.
• Dischargeable.
• Easy washing off.

Reaction :  Dye – SO₂ – CH = CH₂                             Dye – SO₂ – CH₂-CH₂ – O – Cell.

                                                            Cellulose

#Bi-functional reactive dyes:

     These dyes give a high degree of fixation because it contains two identical or different reactive grouping in the dye molecule.

• High degree of fixation rate.
• Substantiality to fibre.
• Pick –up% is very good.
• Fastness property is good.
• Dye loss possibility is less.

Example: MCT, MFT-VS Type, Cibacron C, Sumafix Supra dyes. MCT- VS Type.

Dye reactivity and Application:

The table gives some examples based to the reactive grouping:

12.9 Scouring:

            Grey fabrics contain fats, waxes, and other impurities. The absorbance of the fabric is adversely affected dye to the presence of these impurities. This leads to the improper dyeing, printing and finishing in the subsequent process. These impurities are removed from the fabric by a chemical treatment. This chemical treatment is called scouring process.

In generally, the process by which all the natural and added impurities except natural coloring matter are removed is called scouring. It is also known as kiering, kier-boiling.

12.10  Purpose of scouring process:

–          Used to make the fabric more absorbent.

–          Clean the fabric with the help of NaOH.

–          Remove all impurities both natural and added from the desized fabric.

12.11 Bleaching:

            Bleaching is a process which removes the natural nitrogenous matters, i.e. dirt, dust, husk, broken seed, protein, leaf etc. from the fabric and make it white by oxidizing or chemical treatment.

Purpose of Bleaching:

• To remove all the natural colouring materials.
• To impart adequate whiteness to the fabric.
• It changes the textile materials which are hydrophobic in nature.
• It increases the dye absorption ability of the textile materials.
• It helps to produce an even shade during dyeing operation.
• To impart the wet ability of the fabric which is necessary for further treatment and in domestic uses.

N.B: Actually, Bleaching process can not remove the full colour just break-down the colour producing part.

12.12. Bleaching can be done by two ways:

• Oxidation process. (Preferable).
• Reduction process. (Is not preferable because, after some days it becomes yellowish colour on the fabric surface reoxidation process).

12.13. Bleaching agent:

• H₂O₂, i.e. Universal bleaching agent.  So it is used World-wide for its good performance.
• NaOCl, from here free chlorine comes-out. So, it is not used world-wide.
• Ca (OCl)_2.
• NaClO₂. etc.

12.14. Advantages of peroxide bleaching:

• Among the oxidizing agent, only H₂O₂ provides a high bleaching effect at a reasonable cost.
• No changes of reoxidation.
• Peroxide bleaching keeps the fibre quality.
• Cotton can be bleached with H₂O₂ in a single stage.
• In hot, alkaline peroxide has not only a bleaching effect but also a cleaning effect.

Reaction:

H₂O₂                            H⁺ +  HO₂^–

HO₂^–                     OH^– + [O]

[O]   +  [Colorant’s]                      Discolourisation.

H₂O₂ :

• Unstable in higher P^H & Alkaline medium.
• Unstable in higher temperature.
• Stable in lower P^H & Acidic medium.

N.B: To keep stable P^H  we used buffering agent. i.e. Silicates, Phosphates etc.

Specific gravity (S.G):

   The ratio of substances weight and at 4^oC temperature equal volume of weight of water is called specific gravity. Water S.G = 1000 kg/m³

                            Substances weight

S.G =                                                                                      ×ρ^θ

                    At 4^oC temperature equal volume of water

The S.G of salt is most important factor in dyeing because salts help to dye exhaustion or penetration in the fabric.

• If the S.G value of salt is less than standard value. Then dye penetration in to the fabric will not be good. For this reason we will have to notice so that salt & water is not more or less one each another. It will have to keep an equilibrium condition.
• If the S.G of salt is less than the target S.G. Then salt adds by calculating the salt percentage.
• If S.G of salt is increased then fabric will be dark shade. For reducing that a little amount of water is added to light it.

P^H :  The negative logarithm of  Hydrogen Ion is called P^H. P^H is an important factor for dyeing.

• If  P^H  = 0 – 6.9                  Acidic medium.
•      P^H  = 7                          Neutral medium.
•      P^H  = 7.1 – 14              Al kali medium.
• If the P^H is less in dyeing :

–          Shade of the fabric will be variation.

–          Dyes will be hydrolysed.

–          Uneven shade of the fabric.

• If P^H is more, then acid add to decrease or adjust P^H.
• If P^H is less, then Soda adds to increase or adjust P^H.

12.15. Time required for dyeing processing in different parameter:

• Without enzyme + Finishing- then processing time will be required at 8 hrs.
• With enzyme + Finishing – then processing time will be required at 10 – 11 hrs.

N.B: By SLF– groups of colour dyeing action always perform in MIGRATION process.

         Where, Colour chemicals add – (40 – 60)^oC

                                         Dyes add – (40 – 60)^oC

                                         Salts add  –  80 ^oC. Run time 30 min.

                                          Soda adds –  60 ^oC. Run time 30 min.

   By Bezaktive – SMX  groups of colour dyeing action always perform in ISOTHERMAL process.

• Remazol.
• Cibacron.
• Imcozine . where, Colour chemical adds – 60^oC

                                    Dyes adds                   – 60 ^oC

                                    Salt                             – 60 ^oC

                                    Soda                           – 60 ^oC

Here, exhaustion and fixation will be occurred at this same temperature.

12.16 Chemicals which are entered manually:

• Contipon S (10%).
• Reduzin ABC.
• Jinsofter BSK.
• Abutex – AP – 750. (42%)
• Caustic Soda (pearls).
• Glauber’s  salt.
• Soda Ash.
• Cotoblanc –NSR.
• MA- Prep –IN (Scour – AIN)
• Deco soft Jcc (10%).
• Lyogen PES.
•  Dyapol –AB.
• Dyapol –XLF.
• Antisil  Conz.
• Redupal – SU.
• Dyes.
• Jinsofter WCS (Flakes).
• Bluton sun white BVB/BMB.

12.17 Chemicals which are transferred automatically:

• Hydrogen per –oxide (H₂O₂ 35%).
• Reduzin –THN (50%).
• Acetic acid.
• Jinlev CL-225.
• Jintexalate –SQ-117.
• MA- Humi(terge –Ap) .Dark shade
• Hydrostat BM
• Liquid enzyme.
• Zetafix WER.
• Jintex Stab.

N.B: Fixing process is done during dark or deep shade.

N.B: SAS: If shade% is more then salt is added before dyes add. Some times salt is adding two  times in deep shade.

         DAS: If shade% is less then salt is added after dyes adding.

2. Process Requirement:

2.1 Software used:

      In this factory for total dyeing management used three software.

• SIDO MASTER.
• SDM – Used as a planning board.
• DOSA-TEX – Auto dozing Controller.

N.B: The whole industry uses a one software. Its name is “HAQUE –TEX’’ software.

2.2 Key Accessories:

      Key accessories used in this factory for pretreatment to complete dyeing are:

• Salt tank.
• Mixing tank.
• Machine tank.
• Bohme meter.
• P^H meter.
• Eye protecting glass.
• Hand gloves.
• Sewing machine.
• Gum boot.
• Hand lifter for carrying the batch.

2.3. Materials/ Chemical used:

     Following materials or chemicals are used in the pretreatment process:

• Water.
• Steam.
• Compressed air (for yarn dyeing).
• Antifoaming agent. (e.g. Contipon S).
• Detergent. (e.g. Reduzin ABC).
• Wetting agent. (Abutex – Ap-750(42% solution).
• Sequestering agent. (Reduzin ABC).
• Caustic Soda. (NaOH).
• Hydrogen peroxide. ( H₂O₂35%).
• Stabilizer. ( Jintex stab).
• Anti-creasing agent. ( Jinsofter –BSK)
• Hydrogen peroxide killer.( Reduzin –THN)
• Acetic acid.
• Enzymes for neps and dead cotton .(Hydrostat-BM).

3.0 Safety:

      In order to ensure  floor and personnel safety operations are instructed to follow the   safety guide lines given bellow:

• Smoking is strictly prohibited in the factory premises.
• Put on the safety masks while mixing or transferring alkali and acid.
• Operator must be cautious while handling hydrogen peroxide and caustic soda and use hand gloves, eye protecting glass for safety.
• During production, after reaching the optimum temperature(above 80^oC), in case the lid of the machine needs to be opened, operator must depressurize the machine and use hand gloves, eye protecting glass etc. while performing such task for safety.

4. Operation Procedure:

    Operation stuffs for pretreatment to complete dyeing includes below:

• Production manager.
• Assistant production manager.
• Sr. production Executive.
• Production Executive.
• Sr. supervisor
• Supervisor.
• Operator.
• Helper.

4.1 Checklist before operation.

• Checking the programme in Dosa-Tex software.
• Machine set-up.
• Fabric weight.
• Fabric quality.
• Yarn quality.
• Collar design (Tipping/ solid).
• Rib designs (Normal/Lycra).
• Chemical availability.
• Power availability.
• Steam availability.
• Water availability.
• Compressed air.
• Manpower availability.
• Fabric stitch is done properly.

4.2 Operation Procedure.

4.4.1 Scouring& Bleaching recipe:

         In this factory scouring and Bleaching are performed at the same time.

4.4.2. Scouring& Bleaching, Time and Temperature:

          The  Time and Temperature for the Scouring and Bleaching process are given below:

There are two types of cotton dyeing in this factory these are as follows :

1. color dyeing
2. white dyeing ( OBA treated )

there are 3 steps in color dyeing are as follows:

1. pretreatment
2. dyeing &
3. soaping

  pretreatment:

                      the scouring and bleaching is done at a time this factory. The bio-polishing is not always done. If the yarn is not good, then, bio-polishing  is done .Other wise it is not done .

     The scouring and bleaching is described here step by step:

    # Pre-bleaching Process:

                                     Filling the machine with required water

                                      Fabric loading (normal temperature)

At 50^oC  the leveling chemicals are used are given below:

                                                     Enters at dye bath

                                                   Run time 4 minutes at 50^oC

 Temperature raising from 50 ^◦C to   60 ^◦C and during this time the Hydrogen peroxide 35%                                                        is transferring in to the dye bath .

At 60 ^◦ C run time for 2 minutes and the memory level(water level ) is corrected.

Temperature raised from 60 ^◦ C to 110 ^◦ C. During this time the Caustic soda pearls dosing is completed. Though, the

Required time for this increasing temperature is 20 minutes but  maximum in cases it takes 29 minutes to 31 minutes.

                                        Run time  20 minutes at  110 ^◦ C

Cooling from 110 ^◦ c to  95 ^◦ C  . Though the required time for this is 7 minutes but in maximum case it takes 10 to 12 minutes

Rinsing for 15 minutes which helps to decrease temperature from 95 ^◦ C  to 80 ^◦ C . Absorbency of the fabric is tested before the rinsing is stopped.

                                      Acquachron at 80^oC  for 15 min

Sample check(absorbency)

At 80 ^◦ C the Radujin THN (50% sol) is used as per-oxide killer is entered in to the dye bath.

                                   Run time for 10 minutes at 80 ^◦ C

                         The amount of per-oxide is checked if it is OK then

            Rinsing to decrease the temperature to 50 ^◦ C from  80 ^◦ C (acquachron for 17^/)

                                      The dye bath is again filled with water

                                   Then Acetic acid is added in to dye bath

                                    Run for 7 minutes with acetic acid at 50 ^◦ C.

                                                  Then rinsing at 50^oC

                                                        Then Drain.

                                       Pre-bleaching is completed here.

Antipilling/Enzyme treatment( if need):

The bio-polishing is done by Enzyme. This process is described here-

                Filling the machine with require water and enter the below chemical.

                                The above chemicals transferred in to bye bath

                                          Run time 50 minutes at 50 ^◦ C .

                                 pH is checked acceptable value is 4.5 to 5 if ok then,

                                                  the bath is drained

                                     Then water is again taken into bath and

                                    the chemicals Hydrostat –BM and Soda ash

                               Transferred in to the dye bath at normal temperature

                                       Then P^H is checked after 2/3 minutes

                                       Then temperature is raised up  to 80 ^◦ C

                                        Run time for 10 minutes at 80 ^◦ C

                                                     Water is drained 1 min.

                             the required amount of water is taken again in the dye bath

                                               Acetic acid is added at 45 ^◦ C

                                                   Run for 3 minutes

                                                            Rinsing

                                                      Then main drain

                                       Enzyme Treatment is completed here.

 Dyeing Stage:

 Suitable dyestuff is used for dyeing to knit fabrics:

 Reactive dyestuff:

 The introduction of “Reactive dyes” by “ICI” in 1956 is an important landmark in the history of synthetic dyes. These dyes chemically reacts with the fibres (hence the name is reactive dyes) with the formation of covalent bond between the dye and the fibre.Dyeing of cotton fibres with these dyes under mild alkaline conditions resultants in a chlorine atom on the triazin ring which is replaced by an oxygen atom from the cellulose hydroxyl group.

Reaction:  

                   Cell-OH  +  OH                 Cell – O^–  + H₂O

                   Cell – O^– + Dye – Cl^–                   Cell – O – Dye  + Cl^–        

Properties of reactive dyes:

• Water soluble anionic dyes.
• During dyeing process reactive group makes Co-valent bond with fibre and stay in the  part of a fibre.
• Use in cellulosic and protein fibre.
• Any kind of shape produced by this dye.
• Washing fastness is very good.
• Rubbing fastness good.
• Good for making light shade.
• Low cost.
• Easy applicable.
• Fibre reacts with the dye to form covalent bond and become a part of the fibre.

Nature of reactive dyes: A covalent is thirty times stronger than Vander- walls force. Direct dye produce dull shade but reactive dyes produce bright shade.

Objectives of reactive dyes:

• To dyeing the cellulosic and protein fibre.
• To get all kind of shade by using this dyes.
• To increase the wet fastness.
• To increase the rubbing fastness.
• To reduce the cost.

Characteristics of structural features of reactive dyes:

                                                       S – C – B – X

  Where, S is the solubilizing group.

              C is the colored molecule.

              B is the bridging group.

              X is the reactive group.

Some reactive groups:

• DCT ( Dichloro triazine).
• MCT( Mono- chloro triazine).
• MFT( Mono- fluro triazine).
• NT   ( Nicotinyl triazine).
• TCP  ( Tri-chloro Pyrimidine).
• DCQ ( Di-chloro quinoxaline).
• DFCP ( Di-fluro chloro Pyrimidine)

The reactive groups undergo mainly two types of reaction:

• Neucleophilic substitution reaction.
• Neucleophilic addition reaction

Classificatio

  Reactive dyes have been recently classified as;

• Alkali controllable.- which have relatively high reactivity and only moderate substantivity. They are applied at a low temperatures and level dyeing requires careful control of the addition of alkali to start to fixation. Example: DCT, DFCP,and VS.
• Salt- controllable dyes.- these dyes are of relatively low reactivity towards to cotton under alkaline conditions and then the dyeing temperature will be as high as 80⁰C . They have appreciable substantivity and level dyeing requires careful addition of salt to promote exhaustion. Example: TCP, MCT, as well as MFT. Reactive dyes.
• Temperature controllable dyes.- which undergo fixation at high temperatures even under neutral conditions. The NT dyes are in the class.

Basic principle of dyeing cotton with reactive dyes:

 Start dyeing with neutral solution, in presence of salt or gradually added to promote exhaustion.

No reaction of dye with fibre takes place . only absorption and migration of dye in the fibre.

                    Then appropriate alkali is added.

                   Acidic dissociation of cellulose takes place producing cellulosate ion.

                                               This starts the dye fibre reaction.

                                     Dyeing continued until no further dye is taken up.

   Through washing to remove the absorbed unfixed and hydrolyzed dyes.

Three steps of exhaust dyeing process:

• The initial exhaustion phase:  Dyeing is started in neutral solution so that there is little change of the to react with cellulose. During this stage some dyes will be absorbed by the fibres, the amount depends on its substantivity. The dye molecules migrate to promote level dyeing. Sodium chloride or sulphate will some times be present initially or be added gradually to promote exhaustion. The temperature of the bath may also be gradually increased to help penetration of dye into fibre and also assist migration.
• Fixation phase: After in exhaustion phase, the P^H of the dye bath is increased by complete or gradual addition of the appropriate type and amount of alkali. This causes dissociation of some of the hydroxyl groups in cellulose and cellulosate ions begin to react of the dye. The fixation process then results in additional dye absorption. Dye absorption from solution and reaction of the fibre then progress until no further dye is taken up.
• Washing phase: The dyed and rinsed fabric contains dye bonded to the cellulose, absorbed but unreacted dye, as well as hydrolyzed dye. There will also be residual alkali and salt which is relatively easy to remove by successive rinsing in cold and warm water. Maximum unfixed dyes should be washed out as much as possible. If this is not done, staining of materials in subsequent washing will result. Thorough washing using boiling detergent solution(soaping) eliminates the unfixed dyes. Soaping is repeated for deep dyeings or the remaining unfixed dye should be complexed with a cationic agent.

Cold brand reactive dyes:

          The  reactivity of the dyes is due to the chlorine atoms attached to the triazine ring. When two chlorine atoms are present in the dye molecule as in the case of Procion Yellow R, one of the chlorine atoms is so reactive that it reacts with the cellulose even at room temperature(20-30^oC) in the presence of alkali. Hence, such reactive dyes are called cold brand reactive dyes.

Hot brand reactive dyes:

         When only one chlorine atom is present in the dye molecule, the reactivity of the dye decreases considerably and the dyeing has to be carried out at a higher temperature(65- 80^oc).

Hence these dyes are called hot brand reactive dyes.

Vinyl Sulphone reactive dyes:

       Reactive dyes belonging to another reactive system( vinyl Sulphone system) have also become popular. Remazol dyes belong to this class. These are marketed in the form of Sulphatoethyle Sulphone dyes which when treated with mild alkali generates the vinyl group that in turns reacts with ionized cellulose to form the dye fibre bond.

• Excellent brightness.
• Wet fastness good.
• Dischargeable.
• Easy washing off.

Reaction :  Dye – SO₂ – CH = CH₂                             Dye – SO₂ – CH₂-CH₂ – O – Cell.

                                                            Cellulose

#Bi-functional reactive dyes:

     These dyes give a high degree of fixation because it contains two identical or different reactive grouping in the dye molecule.

• High degree of fixation rate.
• Substantiality to fibre.
• Pick –up% is very good.
• Fastness property is good.
• Dye loss possibility is less.

Example: MCT, MFT-VS Type, Cibacron C, Sumafix Supra dyes. MCT- VS Type.

Dye reactivity and Application:

The table gives some examples based to the reactive grouping:

Disadvantages of reactive dyes:

The main disadvantages of the reactive dyes are:

• Hydrolyses of the dye.
• Wastage of salt.

Hydrolyses of dyes:

At the same time when the dyes react with cellulose under alkaline condition, a certain amount of dyes also react with water, thereby removing the particular reactive group from the dyes. When this happens, the dye is said to be hydrolysed and is unable to react with the fibre anymore.

Reaction: Dye – Cl^–  +  H⁺ – OH^–                   Dye – OH + HCl

Problem Create during dyeing by hydrolyzing:

• Slower reaction .
•  Reduces the efficiency of the fixation process.
• As it’s  a colored dyes, during subsequent washing may be possibility to colour bleed from the fabric.

Some reactive dyestuff:

For cotton:

• Amcazol.(1:20)
• Imcozine.(1:10)
• Bezaktive S- max & S-LF.
• Remazol RR.(1:10)
• Solacion. .(1:20)
• Drimarine – XN.(1:10)
• Cibacron. (1:10)
• Drimarine- CL.(1:10)
• Dychu – Fix.(1:10)
• Synozol.(1:10)
• Kimsoline.(1:10)
• Jakazole.(1:10)

For Polyester:

• Taicron HWT
• Taicron XFT
• Dianix CC
• Dorospers Red XLD
• Lumacron Yellow S6GL 200%
• Lumacron Red SCBN
• Tex Cotech Sunfix Red S3B 50%
• Lumacron Turq. Blue SGL
• Dorospers  Crimson

Dyeing Preparation Procedures:

1. 01.  For light colour:

1. Water temperature : 60^oC

Dyes weight           : 500 – 1000gm

                        Water                     : 45 litres.

                        Dye solution time  : 10 min.

                        Filtering time         : 15 min.

                        Mixing time           : 10 min

                        Total time              : 30 – 35 min.

2. Water temperature : 60^oC.

Dyes weight           : 1000 – 2000gm

Water                     : 65 litres.

Dyes solution time:   10 min.

Filtering time        : 15 min.

Mixing time          : 10 min.

Total time              : 30 – 35 min.

1. 02.  For medium colour:  

                  Water temperature : 60^oC.

                   Dyes weight          : 10 – 15 kg.

                   Water                    :  70 litres.

                   Dye solution time : 20 min.

                   Filtering time        : 15 min.

                   Mixing time          : 10 min.

                   Total time             : 45 – 50 min.

1. 03.  For dark colour: 

                  Water temperature : 60^oC

                   Dyes weight          : 30 – 40 kg.

                   Water                    : 120 – 130 L

                   Dye solution time : 30 min.

                   Filtering time        : 15 min.

                   Mixing time          : 15 min.

                   Total time             : 60 min.

Dyeing process/method for fabric dyeing:

There are  7 types of dyeing methods apply in this factory.

• Isothermal process.
• Critical migration Process.
• Hot brand process(Turquoise colour).
• 100% Polyester dyeing process.
• CVC fabric dyeing process.
• White dyeing process.
• Bio-scouring method.

Dyeing :

    There are mainly used 3 types of color dyeing processes. e.g.

1. Isothermal  method
2. Migration method
3. Turquoise method

1. Isothermal Process:

        In this  method dyes, salt, soda all are dozed at same temperature. (at 60 ^◦ C).

        Fixation time depends on shade% : up to  2% = 30 min

                                                                     2 – 5% = 40 min.

                                                                Above 5% = 50 min.

 (Remazol, Amcazol, Imcozine, Bezaktive S-max, Drimarine –CL are include in this group).

Process flow chart for (Dyeing SAS):

Filling the machine with required water.

Then dosing the required colour chemical as bellow:

Then temperature raise at 60^oC

Run time 2 min at 60^oC

Then Check the P^H of the solution ( P^H Control 6 to 7 ).

Then enter the dyes group for producing colour according to shade%

Dozing time 15 min

Run time 20 min at 60^oC

After that enter the required amount of Glauber’s salt at 60^oC

Dozing time 20 min

 Check the S.G of Salt (1-1.050)

Run time 20 min at 60^oC

Then enter the required amount of Soda ash at 60^oC

Dozing time 30 min

P^H Check of Soda ash(10.5 -11.78).

Then run time 40 min at 60^oC

Then cut the dyed sample for matching shade within 5/ 20 / 35 min.If ok the sample.

Then drain out the water

Soaping  

The soaping is the 3^rd stage. It is done after dyeing. A typical process is described here:

Draining water

Filling with water 15 min

Rinsing for a certain time at 60 ^◦ C

                                                  Then Acquachron 9 min at 60^oC

Acetic acid transfer into the dye bath at 60^oC

Run for 3 /4 /5 minutes

                P^H is checked and acceptable vale is 6 to 7

Raising temperature up to 90 ^◦ C & Detergent is added

       Sample check                        Treating for 10 minutes

Rinsing is done by draining water.

Fixing and softening: 

It is the 4^th and last stage. It is done after soaping. A typical method of fixing and softening  is as follows:

Draining the dye bath

Filling with water

Sample check, if ok then,

Zetafix WER(Fixer) dozing to for 10 minutes

Acetic acid and Crosoft  NBC(10% solution of 6 gm/l)

Use softener dozing for 10 minutes

        P^H is checked (4.8 – 5)

Running time is (15 – 30) minutes.

Draining the dye bath.

Unload the dyed goods.

2. Critical migration :

    In this method the leveling agent and dyes are dosed at normal temperature (40 –45)^oC

          Then the temperature raised at 80oC and the salt is dosed at 80 ^◦ C.    Then alkali is

dosed at Cooling temperature at 60^oC.

Fixation time depends on the shade%:  Up to 4% = 60 min.

                                                               Above4% = 90 min.

(Bezaktive S-LF, Imcozine dyes group include this process).

Dyeing stage:

Colour chemical enters  at 40^oC

Run time at 4 min.

Then temperature increases at 80^oC

    Then go to the next process ( Soaping, Softening & fixing.)

3. Hot brand process ( Turquoise Process):   

           In this process ,Dyes, salt , soda ash, and other chemicals are dozing at 60 ^◦ C , then

           the temperature is raised at 80^oC. At 80^oC the process runs for 40 to 60 mins.

           Fixation time depends on the shade% : Up to 1% = 20 min.

                                                               1 – 2%    = 30 min.

                                                            Above 2% = 40 min.

            Turq. Solazol(ex- Dark –Blue WR) include this process.

Dyeing stage:

Filling the machine with required water.

Then dosing the required colour chemical as bellow:

The above chemicals are dosing at 60^oC

Run time 3 min

Then preparation of dyes are dosing at 60^oC

Run time 10  min at 60^oC

Then Check the P^H of the solution ( P^H Control 6 to 7 ).

                                      Then dosing the Glauber’s salt at 60^oC

Dozing time 21 min

Run time 20 min at 60^oC

Check the S.G of Salt (1-1.050)

                            Then enter the required amount of Soda ash at 60^oC

Dozing time 30 min

P^H Check of Soda ash(10.5 -11.78).

                                                      After that run time 30 min

                                         Then raises the temperature at 80 to 85^oC

                                                Then run time 40 min at 80 – 85^oC

Then cut the dyed sample for matching shade within 5/ 20 / 35 min.If ok the sample.

Then drain out the water.(complete the dyeing stage)

White Dyeing Process:     

                                Treating with Soda Ash, Contipon S(Anti foaming agent) for 15 minutes at  50 ^◦ C added of  optical brightener at 50 ^◦ C for 20 minutes followed by treating at 80 ^◦ C  for 25 minutes.

100%Polyester Dyeing Process:

                            Polyester dyeing is done at 130 ^◦ C  without carrier . In this process there is no required any salt and soda . But requires it leveling chemicals to performs this process. It also requires acid, According to dyes group  to maintain P^H. If Dianix – CC group of dyes then P^H control 4.5 – 5 and if the –XFT groups of dyes the P^H control 3 – 3.9.

Fixation time depends on the shade% : Up to 1% = 20 min.

                                                                     1-2%  = 30 min.

                                                             Above 2% = 40 min.

Step the 100% polyester dyeing process with disperse Dye-stuff:

The sequence of dyeing process with Disperse dyes is as follows:

1. Take water in the machine bath at required level.
2. Then add Detergent, Sequestering agent, Anti-creasing agent, Dispersing agent.
3. Circulate the fabric for 5 mins at 50^oC.
4. Add acetic acid and circulate for 5 mins at 50^oC.
5. Check P^H of the dye bath.
6. Add dye solution for linear dosing and circulate the for 10 mins at 50^oC.
7. Circulate the fabric and raise the temperature at 130^oC.
8. Continuing Circulate the fabric for 30 – 40 mins at a constant temperature at 130^oC.
9. Circulate the fabric and decrease the temperature at 60^oC.
10. Then Check the shade with approved shade.
11. Rinse and Drain.

For reduction Process:

12. Add caustic soda and circulate for 3 mins at 50^oC.
13. Add Hydrose and raise the temperature at 80^oC.
14. Continue Circulating the fabric for 15 mins at constant temperature at 80^oC.
15. Then Drain.
16. Add acetic acid and circulating for 10 mins at 60^oC.
17. At last final Drain.
18. Unload.

Graphical Representation of Dyeing with Disperse Dye-stuff:

The dyeing process with Disperse dye –stuff can be graphically represented as bellow:

Where,

1. Detergent.
2. Anti- creasing agent.
3. Sequestering agent
4. Dispersing agent.

                     Where,

                                  D    = Caustic Soda.

                                  E    = Hydrose.

                                  F    = Acetic acid.

Reduction Process:

                                   If the shade% is above .5% then reduction will have to be done.       Required Chemicals:

                                 Sodium hydrose:  2 g/l.

                                 Caustic soda      : 2 g/l.

                                  Temp.               : 80^oC

                                   Time                : 30 min

But, if the shade% is above 2, then Redupal –SU 1 g/l will have to used.

1. Process Definition For Blended Fabrics:

1.1.  Poly- Cotton Blend Fabric:

The yarn mixing by polyester fibre and cotton fibre with each other during yarn preparation process is known as Poly – Cotton blended yarn. Generally, two types of polyester- cotton blended yarn are produced. These are:

1. 65% Polyester + 35% Cotton = PC or TC.
2. 40% Polyester + 60% Cotton = CVC (Cheap value of cotton).

1.2.  Pre-treatment process for Blended fabric:

Pre-treatment process for polyester – cotton blended fabric is similar to the 100% cotton pre-treatment process.

1.3.  Dyeing process for Blended fabric:

Two types of dyeing method are used to dye blended fabric.

a)      One bath dyeing method.

b)      Two bath dyeing method.

1.4.  One bath dyeing method:

One bath dyeing method is a dyeing process whereby, polyester part and cotton part are dyed together in one bath.

1.5.  Two bath method:

Two bath dyeing method is a dyeing process whereby, polyester part and cotton part are dyed separately in separate bath.

 N.B: In this factory Used One Bath Dyeing Method for CVC fabric Dyeing.

1.6. CVC fabric dyeing process:

In this process, at first the polyester part is dyeing at high temperature e.g. 130-135^oC. After completing the polyester part dyeing then cotton part is dyeing by using requires chemicals and control require temperature.

1.7. The sequence of dyeing process with Disperse dyes is as follows 🙁 Polyester Part + Cotton part Dyeing) by using One Bath Dyeing Method:

                  1. Take water in the machine bath at required level.

2. Then add Detergent, Sequestering agent, Anti-creasing agent, Dispersing agent.

3. Circulate the fabric for 5 mins at 50^oC.

4. Add acetic acid and circulate for 5 mins at 50^oC.

5. Add Glauber’s Salt and circulate for 5 mins at 50^oC.

6. Check P^H of the dye bath.

7. Add Polyester dye solution by linear dosing and circulate the fabrics for 10 mins at 50^oC.

8. Add Cotton dye solution by linear dosing and circulate the fabrics for 10 mins at 50^oC.

                  9. Circulate the fabric and raise the temperature at 130^oC.

                10. Continuing Circulate the fabric for 30 – 40 mins at a constant temperature at 130^oC.

                11. Circulate the fabric and decrease the temperature at 70^oC.

                12. Then Check the shade of Polyester Part with approved shade.

             13. Circulate the fabric and raise the temperature at 82^oC.

             14. Continuing Circulate the fabric for 30 – 40 mins at a constant temperature at  82^oC.

             15. Add Soda ash by Curve dosing and continue circulating the fabric for 30 – 40 mins at 82^oC.

             16.  Circulate the fabric and decrease the temperature at 70^oC.

             17.  Then Check the shade of Cotton Part with approved shade.

             18.  Rinse and Drain.

             19. Add acetic acid and circulate for 10 mins at 60^oC.

             20. Drain.

             21. Add Soaping Chemical and circulate for 10 mins at 95^oC.

             22. Drain.

             23. Circulate the fabric for 10 mins at 70^oC.

             24. Drain.

             25. Unload.

1.8. Graphical representation of One bath Dyeing Process:

 The One bath dyeing process for Poly – Cotton blended fabric can be graphically represented by as bellow:

Where,

                                              A = 1. Detergent.                        C = 1. Glauber’s Salt.

                                                     2. Anti- creasing agent.

                                                     3. Sequestering agent.          D = 1. Polyester Dye.

                                                     4. Dispersing agent.

                                             B = 1. Acetic acid.                        E = 1. Cotton Dye.

                                                                                                   F = 1. Soda Ash.

Bio – Scouring Process:

 Bio- Scouring is a one kind of dyeing process. There is not required any pre –bleaching process. This is not done available. But in only heavy deep shade or dark shade (Black shade) this process is applied directly for dyeing without bleaching. 

    Antipilling treatment:

Filling the machine with required level of water and enter the below chemical.

The above chemicals transferred in to bye bath

Run time 50 minutes at 50 ^◦ C.

P^H is checked acceptable value is 4.5 to 5 if ok then,

The bath is drained

Then water is again taken into bath and

the chemicals Hydrostat –BM and Soda ash

Transferred in to the dye bath at normal temperature

  Then P^H is checked after 2/3 minutes

                      Then temperature is raised up to 80 ^◦ C

           Run time for 10 minutes at 80 ^◦ C

              Water is drained 1 min.

                        the required amount of water is taken again in the dye bath

Acetic acid is added at 45 ^◦ C

               Run for 3 minutes

             Rinsing

              Then main drain

                   Enzyme Treatment is completed here.

Bio Scouring Dyeing:

Again filling the machine with required level of water.

Then enter the leveling chemical (MA Prep- IN (SCOUR AIN) at normal temperature.

Raising the temperature at 60^oC

Run time 5 min

Then dosing the dyes at 60^oCDosing time 19 min

Run time 15 min

Then enter the Glauber’s Salt at 60^oC.

Check the S.G = 1.050

Run time 10 min

After that dosing Soda ash at 60^oC

Dosing time 14 min

Run time (3-5) min at 60^oC

Then dosing Caustic Soda (Flakes) at 60^oC

Check the P^H = (10.5-11.5)

Dosing time 8 -10 min

Run time 3 min

Sample Check. if ok

Soaping   

The soaping is the 3^rd stage. It is done after dyeing. A typical process is described here:

Draining water

Filling with water 15 min

Rinsing for a certain time at 60 ^◦ C

                                                  Then Acquachron 9 min at 60^oC

Acetic acid transfer into the dye bath at 60^oC

Run for 3 /4 /5 minutes

               P^H is checked and acceptable vale is 6 to 7

Raising temperature up to 90 ^◦ C & Detergent is added

         Sample check                        Treating for 10 minutes

Rinsing is done by draining water.

Fixing and softening : 

It is the 4^th and last stage. It is done after soaping. A typical method of fixing and softening  is as follows:

Draining the dye bath

Filling with water

Sample check, if ok then,

Zetafix WER (Fixer) dozing for 10 minutes at 45^oC

Acetic acid and Crosoft NBC (10% solution of 6 gm/l) at 45^oC

Use softener dozing for 10 minutes

        P^H is checked (4.8 – 5)

Running time is (15 – 30) minutes at 45^oC

Draining the dye bath.

 Unload the dyed goods.

Stripe fabric dyeing Process:

Filling the machine with required water.

Then fabric is loaded

Then temperature is raised from 35 to 60^oC

Then Antisil. Conz chemical is dosed at 60^oC

Run time 20 min at 60^oC

Then acquachron is done for 18 min.

And temperature fall 60 to 45^oC

Drain  for 2 min

Then again filling the machine with required water at 45^oC for 2 min

The temperature is raised at 45 to 60^oC

After that enter the chemical Crosoft NBC + Acid for dozing within 10 min

Run time 20 min.

Then ok and draining out the water

Unload the stripe washed goods

Re-dyeing Process / Shade dyeing Process:

When the dyed sample is not totally match with the approved shade than only for testing this process is applied for getting the desirable shade. So, this process is called Re-dyeing process. But this not our desire to apply this process.

Procedure:

1. Cut the dyed fabric 12^// × 12^//.
2. Then take 10 litre water.
3. Then add .5grm dyes in this water at 70^oC.
4. After that  stirring very well for 10 min.
5. Then take –out the fabric from the bath.
6. Then at 60^oC temperature with 2 litre of water the hot wash and cold wash will be done.
7. Then the fabric is dried and observed the dyed sample with approved shade.

Dyeing Diagram of this factory is given bellow:

Testing

   There are 7 tests are required for cotton dyeing process which are

1. After completing the pretreatment :

–          absorbency is tested and

–          Whiteness is tested.

–          Residual per-oxide is tested

2. During Bio-polishing when, washing agent(hydrostat –BM ) and Enzyme        ( Bio-polish) enter then after 2 or 3 minutes pH is tested and the accepted range is 4.5 to 5.

3. During Bio-polishing when again washing agent (Hydrostat BM) and Soda Ash enter then again pH is tested acceptable range is 8 to 9.

4. During dyeing When the sequestering agent (Jintexalate SQ 117), leveling agent (Jintex RLA), acetic acid, anti-creasing agent(Jinsofter BSK) and antifoaming agent (Contipon  S 10% solution ) enter then after 2 or 3 minutes pH is tested and the acceptable range is 6 to 7.

5. During dyeing When Glauber’s salt enter then after 2 or 3 minutes specific gravity is tested.

6. During dyeing When soda ash enter for 10 minutes, P^H is tested and the acceptable value is 11.5.

7. During soaping When acetic acid into the bath then after 5 minutes the pH is checked and the acceptable range is 6 to 7.

In dyeing the most important chemicals are:

–          Salt.

–          Soda Ash.

–          Caustic Soda.

The Chemicals for dyeing is as follows

Graphical representation of Specific gravity at calculation (Na₂SO₄):

List of machines in Finishing Section:

Fabric Finishing Section:

Sequence of dyed fabric Finishing:

Dyed fabric

Hydro             Dryer       Slitting        Stentering           Compacting (Open) (Dry).

Slitting

                       Calendaring. (Tube).

Stentering

Compacting

Inspection

Delivery (Open). (Wet)

1. Process definitions:

1.1.  Textile Finishing:

The term ‘Textile Finishing’ in a broad sense, covers all the purposes which the fabric undergoes after leaving the loom or knitting machine to the stage at which it enters the market. But in a restricted sense, it is the term used for a series of processes to which all bleached, dyed, printed and certain grey fabrics are subjected before they put on the market. In fact, Finishing includes the final treatment of every kind of fabric made from every kind of fabric.

1.2.  Object of finishing:

• To render textile goods fit for their purposes or end use.
• To improve the serviceability of the fabric.
• To soften the fabric.
• To control the dimensional stability of the fabric.
• To upgrade the fabric and to impart a smooth, silky touch and to the fabric etc.

1.3.  Important textile Finishing:

• Crease resistance.
• Filling.
• Softening.
• Stiffening.
• Water-repellency.
• Mildew-proofing.
• Moth-proofing.
• Flame –retardant.
• Antistatic finishing.
• Soil resistance.etc.

1.4.  Factors affecting the finishing technique:

• Nature of the fabric: Chemical composition, state, weave etc. This determines the appearance i.e. transparency, Luster, Fullness, weight, whiteness etc.
• The physical properties of the fabric: i.e. Feel, softness, stiffness, tensile strength, elongation, shrinkage properties, insulation etc.
• The receptivity of the fabric for absorbing various finishing preparation.
• The susceptibility of the material to chemical modification.

1.5.  Classification of finishing:

• Physical or Mechanical finish: Raising/ Brushing, shearing, Calendaring, Sanforizing etc.
• Chemical finish: Crease-resistance, soil resistance, flame-retardant, water-proofing, Antibacterial, Wicking finish, Saliva finish etc.

1.6.  Sueding machine:

When a very mild form of raising may be produced on cotton or wool goods by Sueding machine as result the fabric feeling very smooth and soft is called Sueding. Its another name is peach finish or ultra soft.

  Function:

• Light the fabric.
• Lusture the fabric.
• Softer feelings of the fabric
• Smoothness of the fabric.

         N.B: Fabric is peach finished by the buyer requirement.

1.7.  Brushing machine:

       The brushing process is applied after raising to make the cloth the level and clean. It removes loose fibres and foreign matter which may have entangled with the pile and also can be used to raise the tips of the fibres before raising. Brushing may also use after shearing to remove any loose-cut fibre.

        – Brushing the CVC fabric by using raising machine.

1.8. Shearing:

        The shearing process is also referred to as cutting and cropping. Fundamentally, the simplest machine operates in the same way as a lawn –mower, with revolving knives and an adjustable bedplate.

   Purposes of shearing:

• To clear out the random length fibres and produce a uniform and level pile.
• To reduce the height of the wild fibres and prevent pilling.
• To produce a certain hand feels.
• To improve the colour and appearance of the fabric.
• To produce sculptured effect.

1.8.  Calendaring machine:

Calendaring is an operation carried out on a fabric to improve its aesthetics. In this process, fabric passes between heavily loaded rollers. At the nip, the high pressure, exerted on the fabric, flattens and smoothes its surface. By changing the parameters of the process many other effects can be achieved.

Objectives of Calendaring:

• To upgrade the fabric hand and to impart a smooth, silky touch to the fabric.
• To increase the Lusture of the fabric.
• To compress the fabric and reduce its thickness.
• To improve the opacity of the fabric.
• To reduce the yarn slippage.
• To reduce the air permeability of the fabric by changing its porosity.
• GSM also control by using this machine.

        N.B: Pressure and Heat is applied in calendaring machine depends on the type of finish required.

Chemical use during Hydro:

For White shade:

• Jinsofter WCS (Flakes).
• Microsil – AM.

For Colorful Shade:

• Jinsofter –FS.
• Crosoft – NBC.
• Inosoft – CI.
• Multi soft – ME.
• Acetic acid.

Chemical Solution making for Hydro m/c:

For Colorful shade:

• At first take 250 litre water.
• Then take 25 kg Inosoft –CI.
• Mixing it with water.
• Then take 8 litre solution from that solution.
• Add it with 100 litre water (108 litre).
• Then take 2 kg of Multi-soft –ME.
• After that take (10 – 15) gm Acetic acid, where P^H must be around 5.
• Then total solution = (108 + 12) = 120 Litre.

Silicon softener / Silicon finish:

• P^H must be (4.5 – 5).
• Roller must be cleaned.
• Not allow hot softener.
• If the Silicon softener is applied above at 40^oC then silicon chain is broken fall a spot on the fabric surface.

Stentering machine:

 In textile finishing the most important machine is Stenter. Its another name is Tenter.

The main jobs of this machine are:

• To expand the fabric.
• Shrinkage control along to length wise and width wise.
• GSM control.
• Dia control.
• Heat –setting the lycra fabric.
• To remove wrinkle from the fabric.
• To remove the crease mark from the fabric by stretching.
• To apply the finishing chemical.
• As well as drying the fabric.

Fabric Shrinkage occurs:

• After dyeing of the fabric.
• After washing the fabric due to swelling.
• During squeezing of the fabric.

N. B:  Machine length generally is: 60 – 120 feet. & width – 70 inch.

          But, yet most useable machine – 90 feet is very popular.

A Stenter machine Temperature and Speed depends on:

• Fabrics Types.
• Fabric shade.
• The GSM of the Fabric.

Required finishing Chemical for Stentering m/c:

For White:

                    Jinsofter WCS = 3 kg.

                   Microsil AM     = 1.5 kg. + 100 litre water.

For Colour:

                     Jinsofter FS = 1.5 kg.

                     Inosoft CI   = 1.5 kg.

                      Acetic acid =

                      Water         = 100 litre.

Required finish chemical for TC/PC fabric:

• Tubingal 11-12.
• Siltex – PE -40.

Chemical solution:

(100 litre of water + 1 kg of PE-40 & 11-12 + Acid 15grm).

Shrinkage control:

• Shrinkage is controlled by proper over feeding.
• To apply less or more over feed speed fabrics reduce along to length and increase along to width. Maximum 70 – 75% shrinkage is controlled by using it.

GSM Control:

• GSM is also controlled by applying proper over feeding speed.
• If over feed is more then GSM is also more.
• If Over feed speed is less then GSM is also is less.
• If Dia is more then GSM of the fabric will less.
• If Dia is less then the GSM of the fabric will more.

N.B: If GSM of the fabric is OK then shrinkage is also OK.

Dia Control:

• Dia is controlled by dia controlling meter scale.
• If any fault, GSM of the fabric is reduced then to increase the GSM of the fabric dia will have to be reduced (2 – 3) inch.
• If Over feed speed is more then Dia of the fabric will be more.
• If Over feed speed is less then Dia of the fabric will be less.
• If length is more then width of the fabric is reduced.
• If length is less then width of the fabric is more.

N.B:  Fabric speed is controlled on the fabric dia. Here, Dia less or More fully depends on yarn count and buyer order. Dia is done less or more by using expander

rod.

Single jersey  – small dia (1.5 – 2 ) inch +.

Rib fabric       –  2 – 2.5 inch +.

Interlock         – 3 – 3.5 inch +.

Pique              – 3 – 3.5 inch +.

Over feed:

• GSM Control.
• Shrinkage Control.
• Dia Control.

N.B: Single jersey over feed – 7%.

              Interlock over feed  – 5%.

               Collar over feed     – 3 – 4 %.

     In over feed R/r speed is more than another R/r .  GSM      Speed     .

                                                                                    GSM     speed

Depends on Dia:

Lycra over feed speed – 30 – 35 m/min.

1×1 Rib over feed speed – 28 – 30 m/min.

Single jersey over feed speed – 26 – 27 m/ min.

2×2 Lycra rib over feed speed – 23 – 24 m/min.

Lacoste over feed speed is given more.

Normal over feed speed , 22/23/24/25 m/min.

Compacting machine:

By compacting machine mainly controlled GSM of the fabric. If GSM is controlled then Dia and Shrinkage is also controlled by proper over feeding speed and retard roller.

Interlock fabric compaction – 9 – 12%

Lacoste   fabric compaction  – 10 – 14%.

1×1 Rib fabric   compaction – 8 – 11%.

Lycra fabric compaction      – 10 – 11%.

Single jersey compaction   –   8 -9%

2×2 Rib compaction          –   6 – 7%

N.B:  Here, the amounts of steam depend on fabric shade. The amount of  pressure also depends on fabric types. Compaction% of fabric will  depend on shoe pressure. Compaction% measures by Scale. Dark shade pressure and steam is increased. Many times the dark shade fabric is done to light shade by compacting m/c – 2.

Maximum production 24 hours around 7 tons. But compactor-2 maximum production 10 tons.

                                  Before Compacting  – After Compacting

Compaction% =                                                                              × 100%

                                                Before Compacting

Compacting  steam = 3 – 3.5 kg.

Dryer machine:

• It is used to dry the dyed fabric. Here also control the over feed speed, temperature and speed for fabric types.

Fabric types:

• 2×2  Rib over feed =7.2,

              Temperature  = 110 – 115^oC

                           Speed           = 4 m/min.

• 1×1 Rib over feed  = 7.2

             Temperature    = 110 – 115^oC

                           Speed           = 5 m/min.

• CVC fleece   Over feed = 7.2

                      Temperature = 110^oC

                      Speed           = 4 m/min.

• S/J                Over feed =  7.2

                       Temperature = 110 – 115^oC.

                         Speed         = 7.5 m/min.

• Lycra S/ J     Over feed = 7.2

                        Temperature = 110 – 115^oC.

                        Speed            = 5m/min

Some information about finishing:

• Compaction is done to adjust the GSM of the fabric and gained a required GSM.
• Maximum 70 – 75% GSM and Shrinkage is controlled by using Stentering m/c. But in some cases it is done to ok then compacting is not required.
• About 95% fabric is required to Compacting.
• Shrinkage is controlled due to making proper garments by using proper measurement.
• By using steam in compaction to control GSM and fabric construction.
• Temperature Controls the fabric shade.
• Speed depends on fabric types.
• Peach finish is done to fabric face side.
• Brushing is done to fabric back side.
• Maximum 8% process loss is allowable in finishing goods.
• If 10% shrinkage is controlled in Stenter m/c then the fabric will be ok.
• If the shrinkage is not controlled the Dia of the fabric is increase as well as length will be adjust.
• Shrinkage is ok in Lab.
• Shrinkage is controlled to the fabric length -wise and width -wise.
• Temperature 120 ^oC, 170 ^oC, 180^oC – if the shrinkage is not ok then again the fabric is washing and also stentering.
• Lycra fabric extensibility 400%.
• Fabric is dyeing as rope form.

Fabric Inspection and Q.C:

Inspection:

 Activity such as measuring, testing, gauging one or more Characteristics of a product or service and comparing these with specified requirement to determine conformity.

Objectives of inspection:

• Faults verifying of finish goods.
• Dia measure of the finish goods.
• GSM also measure of the finish goods.

Inspection & Grading system:

 4- Point system is applied in this factory:

           Faults length/ Defect Size                  Penalty point

• 0 – 3 inch in length             –           1 point.
• 3 – 6 inch in length             –           2
• 6 – 9 inch in length             –           3
• 9 inch above in length         –           4
• Any holes                            –           4
• Staring mark                       –           4.

N.B:

• Generally, any fabric with less than 40 percent penalty points per 100 sq. yards fabric is allowed to pass.
• However, around the average value should not be exceeded 28 penalty points per 100 sq. yards.
• More than 40 points fault per 100 sq. yards fabric is not acceptable.
• In esquire group acceptable faults rate should not be higher than 28 points.

Formula:

                                           Actual points counted            36

                Total points per 100 sq. yards =                                           ×                            ×100

                                                                    Actual roll length (yds)       Actual width (inch’s)

Disadvantages of 4- point system:

• Regarding of any size of hole it should be calculated the penalty point is 4.
• For starting mark the penalty point is always 4.
• The penalty point is maximum 4 in one linear yards.

Faults that are found in finish fabric by final inspection:

• Thick and thin places of the yarn.
• Barre effect.
• Hole.
• Miss stitch.
• Starting mark.
• Needle or sinker.
• Neps.
• Slubs.
• Dead fibre.
• Foreign fibre.
• Yarn contamination.
• Oil spot.
• Crease mark.
• Bowing.
• Edge mark.
• Crumple.
• Dirt mark.
• Hairiness’
• Patchy.
• Softener Spot.
• Shine mark.
• Colour prominency Fault.
• Dust.
• Join mark.
• Pin hole.

 YARN DYEING SECTION

         Grey Yarn requisition

          Soft coning

           Batching

           Dyeing

             Hydro extractor

           Drying

            Hard coning

            Inspection

          Packing

          Delivery

1.3. Buyers:

                 There are two types of buyers such as,

1. EKL such as C & A , Jordache, Zara , Tesco etc.
2. Out paraty such as Base textile, Novel Harican etc.

1.4. Order:

               There are two types of orders, such as :

                                1. EKL               “Y” order .

                                2. Out party            “C “order.

1.5. The no of yarn dyeing machine, machine brand, country of origin and capacities are given below: 

YARN Dyeing Section: 

 There are two soft winding sections are as follows:

1. Soft  winding section -1.
2. Soft winding section -2.

Two types of soft winding process :

1. Conventional soft winding
2. SSM soft winding

Soft winding section -1:

  There are 15 machines in this section . This soft winding process is called conventional soft winding. The short descriptions of this machine are as follows:

Name of the machines :  Conventional Soft winding machine

Machine function :  Soft winding

Number of heads : 60

Brand name : HWAA

Country of origin : Taiwan

RPM : 1700

Soft winding section-2: 

There are two soft winding machines in this section .  This soft winding process is called SSM soft winding process.

Name of the machine : Soft winding

Number of head : 40

Brand name : SSM

Country of origin: Switzerland

Objectives of soft winding:

• Softly winding the package.
• Make a suitable package for dyeing machine.
• Paper Bobbin wound softly in steel Bobbin or spring bobbin.
• To enter the dye molecule evenly into the fibre inner molecular surface.

Bobbin: 

              There are two types of bobbins . They are :

1. Perforated Bobbin (steel bobbin).
2. Spring Bobbin

  N.B:

• Hole of the steel bobbin are 510.
• Unit -01 total machine 15 pcs. And Unit – 02 total machine 2.
• No. of head each machine is 60 (30 +30).
• Head contains: Bobbin, spindle, tension device, and drum.
• Doffing time depends on Bobbin weight.
• Weight of the steel bobbin without is 280gm.
• Weight of the steel bobbin with yarn is 1440gm.
• Weight of the spring bobbin is 180gm.
• Motor r.p.m of the soft winding machine is 1000.
•  Time depends to wind yarn on bobbin dia.
• If bobbin dia is more, then time will require more.
• If bobbin dia is less, then time will require less.
• In case of cotton, if yarn count is more then time will be required more to wind yarn on bobbin.
• In case of polyester yarn, the more will be denier, the more will be heavy thread. The less will be denier, the less will be thin thread.
• In 100% polyester, filament if denier is more, then winding time will require less. Time require 5 hrs.
•  If denier is less then winding time will required more. Time req. 9hrs.
• Light colour process loss% is more.
• Deep colour process loss% is less.

Gross weight: With cone is called gross weight.

 Net weight: Without cone is called Net weight.

Organic Cotton: Without using of any fertilizer or chemical which cotton is produced naturally is called organic cotton.

Combed yarn:

• Not remain short fibre.
• Smooth surface.
• Less neps.
• Strength more.

Carded yarn:

• Short fibre contains.
• Neps contain more.
• Rough surface.
• Strength less.

Slub yarn: it is one kind of yarn decoration.

Spun yarn: When five yarn ply together to make a single yarn is called spun yarn. It is also called polyester yarn. It is used as sewing thread to sewing the fabric.

Available Polyester yarn:

• 150D.
• 75D.
• 50/2D.

Grey mélange:

                        Grey mélange is produced by the combination of cotton and viscose.

Basically the combination of mélange:

Viz: 34/1:   Cotton% + Viscose% = Mélange.

                    95%       + 5 %         = G.Mel.

                    90%       + 10%        = G.Mel.

                    85%       + 15%       = G.Mel.

                    98%       + 2%/1%        = E.Mel.

Kinds of mélange:

• Grey mélange.
• Andhra mélange.
• Ecru mélange.

Viscose:

               Viscose is one kinds of regenerated fibre. It is produced from cotton linters. It is more amorphous than cotton.

Viscose M.R% = 13. And Cotton M.R% = 8.5%

Viscose%     Blackish Shade.

Density:

              The ratio of mass and volume is called density.

                         Mass

              ρ =

                         Volume

Required time to wind yarn in bobbin count wise:

18 – 20^S     = 1.30hrs.

24 – 26 ^S    = 2.10hrs.

28 ^S            = 2.30hrs.

30 ^S            = 2.40hrs.

32 – 34 ^S    = 3hrs.

50/2 ^S        = 2.10hrs.

Bobbin Weight: (For conventional winding machines)

–          The bobbin weight also varies for these two types of bobbins.

–          For preformatted bobbins  the weight of empty bobbin is 240 gm. But when we take  weight of an empty bobbin then we get 230 gm. It is because the empty bobbin lost some weight for long time using in soft winding.

–         The total weight of bobbin (with yarn) after soft winding varies form 700 gm to 1700 gm . We take weight of a bobbin after soft winding and we get 1535gm. 

–         So the weight of yarn in that bobbin is 1305 (1535-230) gm.

–         For spring bobbin the empty weight we get 175 gm . the total weight of bobbin (with yarn) after soft winding can be highest 1300 gm. We take the weight of a bobbin and we get 1145 gm. So the weight of  yarn in that bobbin is 970( 1145-1175) gm.

Bobbin weight ( for SSM winding machine ) :

–          In SSM soft winding machines only perforated bobbins are used . the perforated bobbins which are used here are not same with the other perforated bobbins which are used in conventional soft winding.

–         The weight of perforated empty bobbins which are used here is 260gm but we take the weight of perforated empty bobbin 255 gm.

–         It is because the empty bobbin lost some weight for long time using.

–         The highest weight of bobbins(with yarn ) after winding can be 1600 gm.

–         We get the total weight of the bobbin (with yarn) after winding 1570gm. So the total weight of yarn will be 1315( 1570-255)gm.

Package density:

 Package density in soft winding for cotton must be 0.36 to 0.40 gm/cm³ and for polyester or CVC it would be higher than 0.40 gm/cm³.

We measure the package density of different bobbins in this section which are :

For filament (Polyester): 

For spun yarn : 

For CVC yarn:

Batching

                    There are many yarn dyeing machines and every machine s have different bobbin capacity , different weighting capacity and the number of spindle is also different which are as follows:

In the batching section  the weight measurement is done care fully.

Dyeing

There are mainly two fibers are dyed here. These are:

1. Cotton fibres and
2. Polyester fibers

The total process for cotton is divided into 4 steps :

1. Pretreatment
2. Dyeing
3. Soaping and
4. Finishing

1. 1.      Pretreatment :

                          The scouring and bleaching is done in are one bath here. A typical process is described here step by step as follows:

                                         Yarn loading at normal temperature

treating at 100º c for 48 minutes with leveling chemicals caustic soda 20 g/l and H₂O₂   40 g/l

                                                     hot drain

                                Hot wash at 80º c for 14 minutes

                      treating with H₂O₂ killer Setavin-PK-(THN)

                                       Overflow for 7 minutes

                          Treating at normal temperature for 7 minutes

                                       Overflow for 7 minutes

1. 2.      Dyeing :

                 There are four types of dyeing methods used in this factory e.g:

1. Isothermal  method
2. Migration method
3. Turquoise method
4. RDT black

1. Isothermal method:

                                          A typical Isothermal method is described here:

                      Treating with leveling chemicals at normal temperature

The dyes, soda ash, caustic soda, and acetic acid enter into the dye bath and treating at 60ºc for 60 minutes.

2. Migration method:

                           A typical migration method is described here :

    Treating with leveling chemicals and dyes at normal temperature

                                    Treating with salt at 80ºc

                                    Treating with alkali at 60ºc

3. Turquoise method : 

                                  Treating with leveling chemicals at normal temperature

Treating with dyes, Glauber’s salt, Soda Ash (light), Caustic soda (pearls) and Acetic acid at 80ºc for 60 minutes

4. RDT Black :

                    Treating at 60ºc for 12 minutes with Reducing agent, Caustic  Soda, Jintex RLA ( sequestering agent)

                                   Treating at 80ºc for 24 minutes with dyes

Treating at 95ºc for 70 minutes with Glauber’s salt, H₂O₂  and Soda Ash light

c. Soaping :

                    It is done with Jintexalate QSE (soaping agent) at 90ºc for 30 minutes. But in case of RDT Black soda ash light is also used.

5. Finishing :

                  The fabric is treated at  60ºc for 18 minutes. With Zetafix-R (WER) used as fixing agent, Abutex AC-720 used as softener and Acetic Acid.

For RDT Black a different process is followed e.g.

Here only a hot wash at 70ºc for 12 minutes is done.

II:  Polyester dyeing:    

                               A typical polyester dyeing method is described here :

    Treating at 130ºc for 30 minutes with leveling agent (LYogen-PES), Acetic acid and dyes

                                  Treating with acetic acid at 70ºc for 12 minutes

                                                  Hydro extraction

Number of Hydro extractor machine:

1. Galvanin Hydro extractor -1
2. Galvanin Hydro extractor – 2
3. Pozzy Hydro extractor.
4. Sample Hydro extractor.

1. 1.      Galvanin Hydro extractor -1 :

                  Capacity: 32 bobbins at a time (460 bobbins at a time in each 8 spindle)

                  Time required: 7 to 9 minutes

                        RPM : after entering the bobbins the RPM increases from zero to after about 7 seconds then it increases up to (1248/1260) and the time required for getting this highest RPM from zero 1.55 minutes. Then the highest RPM remains for about 2.53 minutes the RPM then decreases and comes to zero. The time required for this is about 1.39 minutes. The RPM of the machine comes to zero but the bobbins are still moving in the machine because of inertia the time required to stop the movement of the bobbins is about 24 seconds.

2. Galvanin Hydro extractor – 2:

                  Capacity: 32 bobbins at a time (460 bobbins at a time in each 8 spindle)

                  Time required: 7 to 9 minutes

                        RPM : after entering the bobbins the RPM increases from zero to after about 7 seconds then it increases up to (1260/1272) and the time required for getting this highest RPM from zero 1.55 minutes. Then the highest RPM remains for about 2.53 minutes the RPM then decreases and comes to zero. The time required for this is about 1.39 minutes. The RPM of the machine comes to zero but the bobbins are still moving in the machine because of inertia the time required to stop the movement of the bobbins is about 24 seconds.

3. Pozzy Hydro extractor:

                 It was not working during our internship.

4. Sample Hydro extractor:

             Capacity: 10-14 bobbins at a time (depending upon the size of the bobbins).

• For 100% polyester yarn is only Hydro extractor is enough, dryer is not required.

                                                              Dryer

Number of dryer: 3

1. RF dryer
2. Galvanin dryer-1
3. Galvanin dryer-2

1. RF dryer :

               Drying is done by radio frequency. Here only white and light shaded yarn is dried.

1. 2.      Galvanin dryer -1.

                                      Highest temperature: 88⁰ to 83⁰c

                              Initially the temperature remains normal in the dryer machine. The temperature raises from normal temperature to highest temperature after coming at highest temperature the temperature falls down from this highest temperature to normal temperature, the time required for this is about 15 minutes.

Time required for 1 trolley (320 bobbins): 2 hours to 2.30 hours

Time required for 2 trolleys (640 bobbins): 3.3 hours to 4.30 hours

1. 3.      Galvanin dryer -2:

                            Highest temperature: 86⁰ to 78⁰c

                              Initially the temperature remains normal in the dryer machine. The temperature raises from normal temperature to highest temperature after coming at highest temperature the temperature falls down from this highest temperature to normal temperature, the time required for this is about 3 minutes.

Time required for 1 trolley (320 bobbins): 2.20 hours to 2.50 hours

Time required for 2 trolleys (640 bobbins): 3.50 hours to 4.50 hours

• For TC, PC & CVC the lowest value of temperature is used.
• For deep shade the highest value for medium shade medium value of temperature is used.
• For higher count the lower value and for lower count the higher value is used.

                                                   Hard Winding

 There are 3 sections in hard winding:

1. Hard winding section 1.
2. Hard winding section 2.
3. Hard winding section 3.

1. Hard winding section 1 :

                          Number of machine: 3

                          Number of heads/ machine: 120

                          Production:

                                    For 20^s yarn 2 ton/12 hours

                                    For 30^s yarn 1.5 ton/12 hours

                        Tension control:  tension is controlled by tension plates. There are 7 plates for each head. For lower count the higher tension is applied on yarn. Otherwise the cone would be soft. For higher count the lower tension is applied otherwise the yarn would be break too many times during hard winding.

    2. Hard winding section 2:

                    Number of machine: 2

                    Number of heads/ machine: 84

                    Production:

                                    Around 1 ton.

                                    Tension control:  tension is controlled by tension plates. There are 7 plates for each head. For lower count the higher tension is applied on yarn. Otherwise the cone would be soft. For higher count the lower tension is applied otherwise the yarn would be break too many times during hard winding.

 3. Hard winding section 3:

                    Number of machine: 3

                    Number of heads/ machine: 84

                    Production:  Around 1.5 to 2 tons.

One is used for polyester yarn and the other two are used for other purposes.

Packing

  After the hard winding the cones are supplied to the packing section.  The functions of packing section are:

1. At first they check the cones. If there is any shade variation in the yarns of cones or there any problem in cones so that they would not supplied.
2. If there is no problem then, they cover it with a polyethylene packet. If there is some problem then they reject it.
3. They put some cones with polyethylene packet in a bag. The number of cones in a bag could be 36 to 60 depending upon the size of cones. They put so many cones in a bag so that the total weight may vary form 40 kg to 45 kg. They also write the necessary information’s such as buyer name, lot number etc on the bag.
4. They take the total weight of bag and also calculate the weight of yarn and write it on the card and attach it on the bag and it is then ready for delivery.

Delivery.

In this section the pickings are checked and delivered to other buyers.

LAB AND Q.C SECTION

Testing machine:

There are some machines in quality control and laboratory which are given below:

    The following parameters are checked in quality control section are as follows:

1. Dimensional stability ( spirality) of fabric
2. Shrinkage of fabric
3. Color fastness for
   1. Washing.
   2. Rubbing.
   3. Perspiration.
   4. Light.
4. Pilling resistance of fabric
5. Bursting strength of fabric
6. GSM testing of fabric.
7. Sublimation testing.

  Dimensional stability (spirality) and shrinkage testing of fabric:

          These are tested 4 times:

1. After compacting
2. After the garments produced
3. After stentering
4. After calendaring (hardly)

 Procedure of estimation of dimensional stability:

1. At first 2 marks are given in lengthwise and 2 are given in width wise and the distance between then is recorded.
2. Then the washing is done as buyer’s requirement method. some methods are

1. After washing drying is done
2. Now again the distances between these marks is measured and is recorded.
3. Now by this shrinkage formula shrinkage (%) is measured

                                       Length before wash – length after wash

          Shrinkage (%) =                                                                           X 100

                                                   Length before wash

  and for spirality this formula  is used for  garments.

             D₁ X 100                D₂ X 100

    X =                         +

                   L₁                            L₂

Here,

          D₁ = Distortion at left side of fabric

          D₂ = Distortion at right side of fabric

               L₁= Length of fabric at left side of fabric

          L₂= Length of fabric at right side of fabric

                                                                             X

   And (%) of average spirality =

                                                        2

Washing fastness:

  It can be tested in different methods according to buyer’s requirement. Some methods are as follows for solid dyed fabric:

    At first the fabric is attached with multi fiber fabric by sewing then we treat this as follows:

     Is removed then drying of these and the sewing the washing fastness to color change by comparing with the untreated fabric with the help of grey scale and also washing fastness to staining is measured.

 The method for yarn dyed fabric is as follows-

 For yarn dyed fabrics the fabric is produced by different colored yarn which will be used in the fabric by sample knitting machine then testing is done particularly. If the result is not ok then again total fabric will be produced and the testing will be done with the total fabric. In this case cotton fabric is attached in one side of the fabric and multifiber fabric is attached in other side of the fabric. We have to be careful that the fabric weight must be 2 times higher than the total weight of the multifiber fabric and cotton fabric. The total fabric is known as combo. If the fastness property of combo is acceptable then the fabric will be acceptable for bulk production.

    The grading for staining in yarn dyed fabric may be different for each color. In this case the worst result is taken.

 Washing fastness for solid dyeing is checked normally 3 times e.g.

–          during sample production

–          after compacting /calendaring

–          after printing

–          after garments produced

  For yarn dyed fabric it is checked normally 4 times are as follows:

–          by producing a fabric with  a  particular yarn color

–          by producing the repeat of fabric if required

–          after the garments are produced

–          after printing

 Rubbing fastness: 

 For rubbing fastness we have to follow these procedures are as follows:

–          take the sample as along as that can cover the metallic mounting plate

–          then the crocking cloth is set in the crocking in ( peg) with clip

–          then the test specimen is rubbed to and fro 10 times

–          finally the crocking cloth is removed from the peg

–          again a wet crocking cloth is taken and previous procedures are again followed.

We have done the rubbing and washing fastness of a fabric which is attached here: 

Perspiration test:

   Perspiration fastnesses are as follows:

1. Fastness to water
2. Fastness to acid
3. Fastness to alkali

It can be done in the following process –

–          at first perspiration solution is produced. There are 3 types of solution that is :

                      water: produced by only distilled water.

     Acid solution:

pH should be 4.3 ± 0.2

Alkali solution:

 pH should be 8 ± 0.2

–          then the 100mX 4 m cm of fabric is taken and is put into the solution for 30 minutes

–          then the fabric is squeezed by

–          the fabric is dired and the fastness is measured

Tested sample Attached:

light fastness:

               for the fastness the fabric is placed in the frame and is placed under light for 20 hours. Then it is compared with the untreated fabric and the fastness is graded by a blue scale.

Tested Sample attached:

Bursting strength:

                            The fabric is placed in this machine and the air is to pass through  the fabric at a time seam or fabric teared and the result is taken at that time.

   GSM test :

           GSM means gram per meter square. It is measured by the GSM cutter. It is placed in the fabric and a portion is cut and then it is weighted.

 The diameter of the GSM cutter is 11.3 cm

                                     3.14X d²             3.14 X (0.113)²

We know, area, A =                        =                                         m²

                                        4                              4

                                   = 0.01 m²

 If the weight of the fabric is x gm which we get by cutting the GSM cutter then,

 Weight of 0.01 m² is x gm

                                       x

Weight of     01 m² is          gm

                                      0.01

                          = 100 x

So the weight is multiplied by 100 to get the correct GSM which we get by cutting the GSM cutter.

 Pilling resistance:

                              It is done only for the solid dyed fabrics. The procedure is as follows –

–          8 pieces of sample are taken and two edges are attached by sewing.

–          These are placed on 8 rubber pads

–          The machine is started with these rubber pads and 15000 cycles are completed for 4 hours.

–          Then by comparing the treated samples and untreated samples with the help of grey scale the grading is done.

Tested sample:

Sublimation test:

 Requiring two colour of yarn as ply.

• One is colour.
• Another is white.

Test: keep the sample at 150^oC for five minute and 180^oC for 5 mins. Total 10 min.

Count test procedure:

In case of cotton yarn Single ply:

• Set the m/c at 110 rev.
• Weight the sample in grams.
• 64.8 are to be divided by sample weight say sample weight ‘p’ gram.
• Then Cotton= 64.8 / p = ‘a’ Ne.

Incase of filament yarn:

• Set the m/c at 100 rev.
• Weight the sample in grams.
• 90 is to be multiplied by sample weight. Say, sample weight ‘q’ gram.
• Count in denier = 90 ×q = ‘b’ D.

Conversion:

• Tex = Denier × .111
• Cotton count to denier = 5315/ cotton count. = Denier.
• Denier to Cotton count = 5315/ Denier = Cotton count.

P^H test of garments:

• Take 10 gram of sample.
• Then cut the sample into small piece.
• Take 100cc of water in a conical flax.
• After that small piece of keep in conical flax.
• Then load on rapid m/c at 90^oC for 30mins.
• After finishing the unload the sample.
• Then keep it at 12 hrs rest condition.
• Then check P^H of the fabric.
• P^H of the fabric is 7.81. Acceptable limit is 4-7.8/8.

Laboratory

The total process flow chart for approval shade up to garments:

      Quality parameter:

                                                       Bulk Dyeing

                                                                                              – C/F to wash -4-5

                                                        Finishing                       – C/F to light – 4 -5.

                                                                                              – C/F to Rubbing – 3, 2

                                                        Cutting                          – C/F to perspiration – 4 -5.

                                                                                     – C/F to water – 4 -5

Garments.

Available dyestuff:

Amcazol, Remazol, Bez.SMX, S2B, SLF, Imcozine, Cibacron.

                                           Dk    Mdm Lt. colour.

N.B:                     Shade% × Fabric weight.

            Dye =                                                    

                                        Stock%

                                   g/l × Total liquor.

Salt =

                                            1000

                                   g/l × total liquor

          Soda =

                                  1000 × Stock%

          Water =     30 – (dye + soda).

The flow chart for laboratory work is as follows:

                                                                                                                                        Swatch

                                      Color selection & recipe calculation

                                               Dyeing sub staff

                                                     Pipetting

                                                  Dyeing process

                                                     Wash off

N.B:

• Less than .5% shade is called Light Shade.
• 0.5% – 1.5% shade is called Medium Shade.
• Above 1.5% Shade is called Deep Shade.

X% Stock solution:

X% stock solution means that 100cc of water contains X gram dyestuffs.

X% dye stuff:

X% dye stuff means that 100grm textile materials contain X gram dyestuff.

Salt test process:

• Have to take salt 40 g/l and Soda 20 g/l.
• For lab test in 100cc water mix 4 g/l salt then check P^H.
• Acceptable limit is 7 – 7.5. If not ok.

Soda test Process:

•  Take 20 g/l in 100cc water.
•  Then check P^H. Acceptable limit is 10.5 – 11. If Ok. If 11.5 above then not ok.

The dyeing Process of different dyes for laboratory is as follows:

The amount of salt and alkali for different dyes percentages are as follows:

           The swatch is taken & then color selection is done. During color selection the color fastness & costing is also checked. Then the Pipetting is done by Robe lab or manually. The dyeing process is the next step followed by a wash off. 

Essential for light colour (Pipetting):

Suppose, Bez. Red SMX   = .05 /.01.

Then 1% Stock solution will have to 10%.

1% stock solution means, (100ml water + 1 gram dyestuff)

10% stock solution:             (9cc water + 1cc dye from above solution.) = .01 – .1

Again for 10% Stock solution: (9cc water + 1cc dye from above solution) = .001 – .01

N.B:

When two groups of dyes are separate. Then whose shade percentage is more that according to that group salt and soda will have to taken.

Colour matching: (pigment theory).

KNITTING

There are submitted the machine list for knitting purposes as below:

Knitting Section: 

Knitting faults:

• Oil spot.
• Loop.
• Hole.
• Start mark.
• Oil line.
• Needle mark.
• Sinker mark.

GSM Control: 

          VDQ Pully Dia       Loop length     GSM         

           VDQ Pully Dia     Loop length       GSM     

GARMENTS 

There are 4 units in garments section in this factory:

 Printing: 

No of printing machine: 2

Production: 7000 – 15000 pcs/ day

Drying (curing) is done by 1 dryer having brand name Sprint (USA).

Embroidery: 

No of machine: 5(one is for sample and the others are for bulk production)

Capacity: 24000 pcs/ day

WASHING PLANT 

         Production per day: 5000- 10000 pcs

• No of washing machine : 2

                            Name of the machine: Smartex

                            Machine function: Washing

                            Weight capacity:  6600 kgs

                            Drum capacity: 3398 lts

                           Yarn of construction: 2006

• Total no of dryer : 7

                           Company name: Century Faith Industrial Ltd.

                           Country of origin:  Taiwan

                           Dryer capacity: one has 30 kg capacity & the rest of the six have

                                                      300 kg capacity.

• There are 5 types of washing are used in this washing plant such as :

1. SiliconeWash (Used for producing slippery effect on the fabric surface)
2. Softener Wash( Used for producing soft effect)
3. NormalWash( Used for producing curling effect)
4. EnzymeWash( Used for bio-polishing )
5. Acid Wash ( Used for color fading )

 MAINTENANCE 

Power

There are 3 sources of power in this factory which are given below:

1. Gas Generator
2. REB
3. Diesel generator

1. Gas Generator:

    No of generator: 3

    Brand name: Weaksha.

    Country of origin: USA.

1. Gas generator 1 :  Capacity around  900 kw/hr
2. Gas generator 2 :  Capacity around  1100 kw/hr
3. Gas generator 3 :  Capacity around  900 kw/hr

2. REB: Capacity around 400 kw/hr

3. Diesel generator:

                        No of generator: 2

                        Brand name: Pedbow

                        Country of origin: UK

                 A. Diesel generator 1:  Capacity around 150 kw/hr

                 B. Diesel generator 2:  Capacity around 150 kw/hr

                                                Boiler

No of boiler: 4

 POWER , WATER & AIR 

MADICAL FACILITY 

Compressor

No of compressor: 4

There is regular maintenance routine for each machine in this factory.

 WATER TREATMENT PLANT 

Water Treatment Plant (WTP)

Number of WTP: 4 (among them 3 is running and the other is under construction)

There are 3 parts in WTP these are:

1. Multi grade filter ( stone)
2. Activated carbon filter ( carbon)
3. Softener ( resin )

After 8 hours the salt water is used for back wash.

Description of W.T.P:

Land water pump by deep tube well is collected to the hard water store tank. Water treatment is done in three steps by three by three filter tanks. The circulations of water at different stages are control by different bulbs like supply bulbs, backwash bulbs, drain bulbs.

Water collected by two parallel pumps is flowed to the stone filter for first filtration. Stone filter consists of six layers of stone of different size and shape. Stone filter helps to remove iron from the water. There is a dosing pump attach with the stone filter for the dosing of sodium hypo chloride. During stone filtration sodium hypo chloride is added to resist the deposition of iron on stone layers which might be rigid and hamper smooth operation.

After completion of stone filtration, water is fed to activated carbon filter for second filtration for the removal of order from the water.

At the end of carbon filtration, water is flowed to the resin filter for final filtration. Here hard water is treated with base exchange complex or zeolites to remove the hardness of water. Zeolites are naturally occurring insoluble mineral of sodium alumina silicate type complex (e.g. NaAlSiO₄.3H₂O ≈ Na-Permutit). When hard water passed through a bed of small particles of such mineral ion exchanger, an ion exchange reaction take place-

2Na-Permutit + Ca (HCO₃)         Ca- Permutit    + 2NaHCO₃ (For temporary hardness)

            2Na-Permutit + CaSO4                 Ca- Permutit   + Na₂sO₄ (For permanent hardness)

 Here the base part (Ca, Mg, Fe) of hard water are replace by Na; result is the salt of Ca, Mg, Fe (Ca-Permutit, Mg-Permutit, Fe-Permutit) and soften the water. After a certain period of times, whole sodium of base exchanger is replace by Ca, Mg, or Fe then it is said to be exhausted; because it will not soften hard water any more and then it need to regenerate by NaCl.

Ca-Permutit + NaCl             2Na – permutit + CaCl₂

 Final filtration makes the water finally soft and drains it to the soft water reserve tank with             the help of a drain bulb. The hardness of water after treatment is 1-2 ppm. For the supply of soft water to the floor a pressure vessel is used. A minimum pressure of (4-5 kg/cm³) is maintained in the pressure vessel for circulation. Air is inject in the vessel to sustain the pressure is required range.

The flow chart of water treatment plant is given bellow –

 Standard water Quality for dye house:

EFFLUENT TREATMENT PLANT

Effluent – Danger of environment:

Effluent is the gaseous, solid or liquid waste, treated or untreated that flows out of a treatment plant, sewer or industrial outfall. Generally, refers to waste discharged into surface waters. From Wikipedia, the free encyclopedia – effluent in the man made sence is generally considered to be pollution, such as outflow from the sewerage treatment facility or discharge from industrial works.

Considering the pollution volume and load of the liquid waste (effluent), wet processing industries are receiving greater attention world-wide and effluent plant (ETP) is becoming an integral part of the industry. Regulating bodies of national and international level are trying to make sure that the legal aspects are not ignored any more. The characteristics of the discharge that exceed consent limit must be treated in some way to conform to the standards set up by them.

On an average, specific water consumption of textile is 100 times per kg of goods processed. About 90 percent of it goods out as effluent.  The total load discharged in the effluent is between 10 to 30 percent or 100 – 300 g/kg of textile materials processed. Of the load 40 – 50 g represent organic matter. With average water consumption, the effluent consumption is total solids 1000 – 3000 mg/l or organic matter 400 – 500 mg/l.

Effluents can be discharged directly to nearest water bodies by treating them to conform standard effluent characteristics. This is done in non city corporation area. In city corporation area, effluents are discharged into nearest sewerage lines (indirect discharge) by giving small bit of treatment that conform indirect discharged standard. Finally, the local authority treats the effluents to get optimum standard.

Typical effluents contain some or all of the following parameters:

–          Oils, fats, and waxes inherent or added to fibre during processing.

–          Vegetables or protein impurities associated with natural fibres.

–          Monomers /oligomers associated with man made fibres.

–           Residual agricultural chemicals from cotton production.

–          Natural pigments, salts and metals.

–          Processing aids such as sizes, spinning oils, knitting oils.

–          Preservatives such as PCP on imports cloths, including pesticides on raw material.

–          Detergent and surface active agent from washing, scouring and bleaching.

–          Enzymes used for desizing.

–          Peroxide and hypo chlorides used as bleaching agent.

–          Unfixed dyes, auxiliaries and alkaline, salts from dyeing operations.

Characteristics of liquid waste:

–          BOD (Biological Oxygen Demand), COD (Chemical Oxygen Demand), AOX (Absorbable Organic Halogen), Metal ion, P^H temperature, etc.

–          The most widely used method for measurement of pollution is the biological oxygen demand after 5 days. it is the measure of the quantity of organic material present in water which is accessible to bacterial attack. Another method is to determined chemical oxygen demand which refers to oxygen consumed in the reaction with a strong oxidizing agent.

For the purpose of general description, at least five distinct categories of waste from the textile industry can be recognized. They are 1. Oxygen demanding materials. 2. Settle able and suspended solids. 3. Many materials impart acidity and alkalinity. 4. Heat. 5. Toxic compounds.

Effect of effluent: The acidity, alkalinity and heat cause destruction of adequate life. Damage crops, by imparting their growth, corrosion of pipe lines and equipments. Suspended solids increase turbidity and interfere with the light transmitting properties of water, photosynthetic and oxygen transfer process.

Method of effluent treatment may be classified broadly into three main categories:

1. Physical. 2. Chemical. 3. Biological.

Physical treatment involves adsorption, sedimentation, floatation, flocculation, coagulation, reverse osmosis/ultra filtration, incineration etc.

Chemical treatment method involves neutralization, reduction, oxidation, electrolysis, ion exchange, etc.

Biological treatment method involves stabilization ponds, aerated lagoons, tricking filters, Activated sludge, anaerobic digestion, and bioagumentation.

There are four stages: preliminary, primary, secondary, and tertiary treatment processes which differ mainly by the number of operations performed on the waste streams.

Current status of ETP in Bangladesh:

According to Dr. Jerry Knapp research about kaliakor industrial area on many industries, some have no knowledge of pollution or ETP_S. Some have no ETP but are concerned about ETP and have limited knowledge. Some are concerned about environment, have ETP and have considered knowledge.

In this circumstance, we expect government will take proper and effective steps to concern industrial about ETP. Regulating bodies of national level should ensure that the legal aspects are not ignored any more. We also expect, industries will be aware to prevent the death of environment.

Process flow Chart for Effluent treatment Plant:

Waste water from dyeing

Mechanical bar edge Crain

Collection tank Or Equalization Tank

Dumping water.

Clarifier settles off (UHRSCC          Ultra high rate solid contact clarifier).

1. Ferrous Sulphate = 5%.

                                                     2.   Soda lime            = 10%

                                                    3.   Polyelectrolyte +HCl (P^H control) + Cl₂

Bio-tower feed tank.

Pumping.

Bio-tower

Aeration tank

Lamella clarifier (secondary).

Chlorination tank

Drain.

                                                       Capacity = 100 m³/hr

                                                       Cost       = 27000 taka/day.

Function of chemical:

                               Ferrous sulphate: It helps to bring the original colour of water.

                               Soda Lime: It helps to precipitate the sludge under the tank surface.       

                                HCl: Its control the P^H of water.

Requirements of ETP:  Dissolve Oxygen (DO) = 4.5 +.

                                             Bio-logical Oxygen Demand (BOD) = <30.

                                             Chemical Oxygen Demand (COD)   = <200.

                                                                                               P^H     = 6.5 – 9.

                               Total Settelable and Suspended Solids (TSS) = <50.

CONCLUSION

Industrial training is an essential part for textile education because it minimizes the gap between theoretical and practical knowledge. Undoubtedly, this industrial training us a lot about textile technology, production process, machineries, industrial management and made us comfortable with industrial life. Besides it give us the first opportunity to work in industry.

During our two month long industrial training at ESQUIRE KNIT COMPOSITE LTD. we got the impression that this factory is a modern export oriented composite knit including industry. Though it was established 12 years ago, it has earned a very good reputation in foreign market for its best quality product over many other export oriented textile mills. They are very much concerned about the quality of their product. That’s why they establish on-line and off-line quality control of each product. They have well equipped and modern textile testing laboratory. They do all the chemical & physical tests of dyed good and the results are very good and within the buyer’s acceptance limit. We have also understood that ESQUIRE KNIT COMPOSITE LTD. cares a lot about then quality. During our training period we have rarely saw many faulty dyeing. If there was any problem it was quickly removed with the help of experienced and skilled production manager. During this period we have never seen any stripping of color from fabric though for this we couldn’t learn how stripping is done but it we think it is good for industry. Moreover they use good quality yarn, dyes, and chemicals in production. The administration, management and chain of command are well organized.

There are some suggestions from us within our limited knowledge

SOME SUGGESTIONS:

• Due to shortage of technical persons (Textile engineer) in night shift, sometimes quality level drops which needs to be minimized by employing technical person in night.
• During our training period we observed that many days one or more batches need for topping which minimize production and increase cost. Action must need to betaken to minimize this problem.
• We observed that, there is lack of understanding between the top level personnel and floor level personnel which may hamper the chain of command.
• The supervisor or floor in-charge did not properly takes care the program of the dyeing machine. So sometime operator escape some procedure which may hamper the quality of the product.
• During the transport of the fabric in the dyeing floor and also during the loading of the m/c, fabrics are soiled for the contact with floor. This makes the fabric/part of the fabric dirty. It may require more scouring/bleaching agent or may create stain making it faulty.
• The machines in dyeing and finishing section should be modernized to control all the parameter properly to minimize the rejection percentage.
• Knitting production need to increase as well as technical persons needs to employ there.
•  The m/c stoppage time should be analyzed and minimized. The maintenance should be carried out when the m/c is out of action (wherever possible) and routine maintenance should be carried out regularly.
• More skilled labor should be used in a project and the overall efficiency will increase.

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LIMITATIONS OF THE REPORT:

–          We can not able to collect the necessary information about printing section properly.

–          Because of secrecy act, the data on costing and marketing activities has not been supplied & hence this report excludes these chapters.

–          We had a very limited time. In spite of our willing to study more details it was not possible to do so.

–          Some of the points in different chapter are not described as these were not available.

–          It is not possible to bind the whole process in such a small frame as this report; Hence our effort was to summarize them.